diff --git a/NAMESPACE b/NAMESPACE
index 050413eb65..05e448d96e 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -89,6 +89,7 @@ S3method(fortify,summary.glht)
 S3method(ggplot,data.frame)
 S3method(ggplot,default)
 S3method(grid.draw,absoluteGrob)
+S3method(grid.draw,ggplot)
 S3method(grobHeight,absoluteGrob)
 S3method(grobHeight,zeroGrob)
 S3method(grobWidth,absoluteGrob)
diff --git a/NEWS b/NEWS
index 16785040a4..5245c016ed 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,10 @@
 ggplot2 1.0.1.9000
 ----------------------------------------------------------------
 
+* `ggsave()` has been simplified a little to make it easier to maintain.
+  It no longer checks that you're printing a ggplot2 object (so now also
+  works with any grid grob) (#970), and always requires a filename.
+
 * `facet_wrap()` more carefully checks its `nrow` and `ncol` arguments
   to ensure that they're specified correctly (@richierocks, #962)
 
diff --git a/R/save.r b/R/save.r
index f2abc75567..10d64ff31c 100644
--- a/R/save.r
+++ b/R/save.r
@@ -1,75 +1,66 @@
-#' Save a ggplot with sensible defaults
+#' Save a ggplot (or other grid object) with sensible defaults
 #'
-#' ggsave is a convenient function for saving a plot.  It defaults to
-#' saving the last plot that you displayed, and for a default size uses
-#' the size of the current graphics device.  It also guesses the type of
-#' graphics device from the extension.  This means the only argument you
-#' need to supply is the filename.
+#' \code{ggsave()} is a convenient function for saving a plot. It defaults to
+#' saving the last plot that you displayed, using the size of the current
+#' graphics device. It also guesses the type of graphics device from the
+#' extension.
 #'
-#' \code{ggsave} currently recognises the extensions eps/ps, tex (pictex),
-#' pdf, jpeg, tiff, png, bmp, svg and wmf (windows only).
-#'
-#' @param filename file name/filename of plot
-#' @param plot plot to save, defaults to last plot displayed
-#' @param device device to use, automatically extract from file name extension
-#' @param path path to save plot to (if you just want to set path and not
-#'    filename)
-#' @param scale scaling factor
-#' @param width width (defaults to the width of current plotting window)
-#' @param height height (defaults to the height of current plotting window)
-#' @param units units for width and height when either one is explicitly specified (in, cm, or mm)
-#' @param dpi dpi to use for raster graphics
-#' @param limitsize when \code{TRUE} (the default), \code{ggsave} will not
+#' @param filename File name to create on disk.
+#' @param plot Plot to save, defaults to last plot displayed.
+#' @param device Device to use. By default, extracted from extension.
+#'   \code{ggsave} currently recognises eps/ps, tex (pictex), pdf, jpeg, tiff,
+#'   png, bmp, svg and wmf (windows only).
+#' @param path Path to save plot to (combined with filename).
+#' @param scale Multiplicative scaling factor.
+#' @param width,height Plot dimensions, defaults to size of current graphics
+#'   device.
+#' @param units Units for width and height when specified explicitly (in, cm,
+#'   or mm)
+#' @param dpi Resolution used for raster outputs.
+#' @param limitsize When \code{TRUE} (the default), \code{ggsave} will not
 #'   save images larger than 50x50 inches, to prevent the common error of
 #'   specifying dimensions in pixels.
-#' @param ... other arguments passed to graphics device
+#' @param ... Other arguments passed on to graphics device
 #' @export
 #' @examples
 #' \dontrun{
-#' ratings <- ggplot(movies, aes(rating)) +
-#'   geom_histogram()
-#' ggplot(movies, aes(length)) +
-#'   geom_histogram()
-#' ggsave("length-hist.pdf")
-#' ggsave("length-hist.png")
-#' ggsave("ratings.pdf", ratings)
-#' ggsave("ratings.pdf", ratings, width=4, height=4)
-#' # make twice as big as on screen
-#' ggsave("ratings.pdf", ratings, scale=2)
+#' ggplot(movies, aes(rating)) + geom_histogram(binwidth = 0.1)
+#'
+#' ggsave("ratings.pdf")
+#' ggsave("ratings.pdf")
+#'
+#' ggsave("ratings.pdf", width = 4, height = 4)
+#' ggsave("ratings.pdf", width = 20, height = 20, units = "cm")
+#'
+#' unlink("ratings.pdf")
+#' unlink("ratings.png")
 #' }
-ggsave <- function(filename = default_name(plot), plot = last_plot(),
-  device = default_device(filename), path = NULL, scale = 1,
-  width = par("din")[1], height = par("din")[2], units = c("in", "cm", "mm"),
-  dpi = 300, limitsize = TRUE, ...) {
-
-  if (!inherits(plot, "ggplot")) stop("plot should be a ggplot2 plot")
+ggsave <- function(filename, plot = last_plot(),
+                   device = default_device(filename), path = NULL, scale = 1,
+                   width = NA, height = NA, units = c("in", "cm", "mm"),
+                   dpi = 300, limitsize = TRUE, ...) {
 
   eps <- ps <- function(..., width, height)
-    grDevices::postscript(..., width=width, height=height, onefile=FALSE,
+    grDevices::postscript(..., width = width, height = height, onefile = FALSE,
       horizontal = FALSE, paper = "special")
   tex <- function(..., width, height)
-    grDevices::pictex(..., width=width, height=height)
-  pdf <- function(..., version="1.4")
-    grDevices::pdf(..., version=version)
+    grDevices::pictex(..., width = width, height = height)
+  pdf <- function(..., version = "1.4")
+    grDevices::pdf(..., version = version)
   svg <- function(...)
     grDevices::svg(...)
   wmf <- function(..., width, height)
-    grDevices::win.metafile(..., width=width, height=height)
+    grDevices::win.metafile(..., width = width, height = height)
   emf <- function(..., width, height)
-    grDevices::win.metafile(..., width=width, height=height)
-
+    grDevices::win.metafile(..., width = width, height = height)
   png <- function(..., width, height)
-    grDevices::png(...,  width=width, height=height, res = dpi, units = "in")
+    grDevices::png(...,  width = width, height = height, res = dpi, units = "in")
   jpg <- jpeg <- function(..., width, height)
-    grDevices::jpeg(..., width=width, height=height, res = dpi, units = "in")
+    grDevices::jpeg(..., width = width, height = height, res = dpi, units = "in")
   bmp <- function(..., width, height)
-    grDevices::bmp(...,  width=width, height=height, res = dpi, units = "in")
+    grDevices::bmp(...,  width = width, height = height, res = dpi, units = "in")
   tiff <- function(..., width, height)
-    grDevices::tiff(..., width=width, height=height, res = dpi, units = "in")
-
-  default_name <- function(plot) {
-    paste(digest.ggplot(plot), ".pdf", sep="")
-  }
+    grDevices::tiff(..., width = width, height = height, res = dpi, units = "in")
 
   default_device <- function(filename) {
     pieces <- strsplit(filename, "\\.")[[1]]
@@ -77,51 +68,45 @@ ggsave <- function(filename = default_name(plot), plot = last_plot(),
     match.fun(ext)
   }
 
-  units <- match.arg(units)
-  convert_to_inches <- function(x, units) {
-    x <- switch(units,
-      `in` = x,
-      cm = x / 2.54,
-      mm = x / 2.54 /10
-    )
-  }
+  dim <- plot_dim(c(width, height), scale = scale, units = units,
+    limitsize = limitsize)
 
-  convert_from_inches <- function(x, units) {
-    x <- switch(units,
-      `in` = x,
-      cm = x * 2.54,
-      mm = x * 2.54 * 10
-    )
+  if (!is.null(path)) {
+    filename <- file.path(path, filename)
   }
+  device(file = filename, width = dim[1], height = dim[2], ...)
+  on.exit(capture.output(dev.off()))
+  grid.draw(plot)
 
-  # dimensions need to be in inches for all graphic devices
-  # convert width and height into inches when they are specified
-  if (!missing(width)) {
-    width <- convert_to_inches(width, units)
-  }
-  if (!missing(height)) {
-    height <- convert_to_inches(height, units)
-  }
-  # if either width or height is not specified, display an information message
-  # units are those specified by the user
-  if (missing(width) || missing(height)) {
-    message("Saving ", prettyNum(convert_from_inches(width * scale, units), digits=3), " x ", prettyNum(convert_from_inches(height * scale, units), digits=3), " ", units, " image")
-  }
+  invisible()
+}
+
+plot_dim <- function(dim = c(NA, NA), scale = 1, units = c("in", "cm", "mm"),
+                      limitsize = TRUE, dim_guess = FALSE) {
+
+
+  units <- match.arg(units)
+  to_inches <- function(x) x / c(`in` = 1, cm = 2.54, mm = 2.54 * 10)[units]
+  from_inches <- function(x) x * c(`in` = 1, cm = 2.54, mm = 2.54 * 10)[units]
 
-  width <- width * scale
-  height <- height * scale
+  dim <- to_inches(dim) * scale
 
-  if (limitsize && (width >= 50 || height >= 50)) {
-    stop("Dimensions exceed 50 inches (height and width are specified in inches/cm/mm, not pixels).",
-      " If you are sure you want these dimensions, use 'limitsize=FALSE'.")
+  if (any(is.na(dim))) {
+    dim[is.na(dim)] <- par("din") * scale
+    dim_f <- prettyNum(from_inches(dim), digits = 3)
+    message("Saving ", dim_f[1], " x ", dim_f[2], " ", units, " image")
   }
 
-  if (!is.null(path)) {
-    filename <- file.path(path, filename)
+  if (limitsize && any(dim >= 50)) {
+    stop("Dimensions exceed 50 inches (height and width are specified in '",
+      units, "' not pixels). If you're sure you a plot that big, use ",
+      "`limitsize = FALSE`.", call. = FALSE)
   }
-  device(file=filename, width=width, height=height, ...)
-  on.exit(capture.output(dev.off()))
-  print(plot)
 
-  invisible()
+  dim
+}
+
+#' @export
+grid.draw.ggplot <- function(x, recording = TRUE) {
+  print(x)
 }
diff --git a/inst/tests/test-ggsave.R b/inst/tests/test-ggsave.R
new file mode 100644
index 0000000000..5968181a0e
--- /dev/null
+++ b/inst/tests/test-ggsave.R
@@ -0,0 +1,22 @@
+context("ggsave")
+
+
+# plot_dim ---------------------------------------------------------------
+
+test_that("guesses and informs if dim not specified", {
+  png(width = 10, height = 10, units = "in", res = 300)
+  on.exit(capture.output(dev.off()))
+
+  expect_message(out <- plot_dim(), "10 x 10")
+  expect_equal(out, c(10, 10))
+})
+
+test_that("warned about large plot unless limitsize = FALSE", {
+  expect_error(plot_dim(c(50, 50)), "exceed 50 inches")
+  expect_equal(plot_dim(c(50, 50), limitsize = FALSE), c(50, 50))
+})
+
+test_that("scale multiplies height & width", {
+  expect_equal(plot_dim(c(10, 10), scale = 1), c(10, 10))
+  expect_equal(plot_dim(c(5, 5), scale = 2), c(10, 10))
+})
diff --git a/man/ggsave.Rd b/man/ggsave.Rd
index 320af1efc5..ebb7f9c6ce 100644
--- a/man/ggsave.Rd
+++ b/man/ggsave.Rd
@@ -2,62 +2,57 @@
 % Please edit documentation in R/save.r
 \name{ggsave}
 \alias{ggsave}
-\title{Save a ggplot with sensible defaults}
+\title{Save a ggplot (or other grid object) with sensible defaults}
 \usage{
-ggsave(filename = default_name(plot), plot = last_plot(),
-  device = default_device(filename), path = NULL, scale = 1,
-  width = par("din")[1], height = par("din")[2], units = c("in", "cm",
-  "mm"), dpi = 300, limitsize = TRUE, ...)
+ggsave(filename, plot = last_plot(), device = default_device(filename),
+  path = NULL, scale = 1, width = NA, height = NA, units = c("in",
+  "cm", "mm"), dpi = 300, limitsize = TRUE, ...)
 }
 \arguments{
-\item{filename}{file name/filename of plot}
+\item{filename}{File name to create on disk.}
 
-\item{plot}{plot to save, defaults to last plot displayed}
+\item{plot}{Plot to save, defaults to last plot displayed.}
 
-\item{device}{device to use, automatically extract from file name extension}
+\item{device}{Device to use. By default, extracted from extension.
+\code{ggsave} currently recognises eps/ps, tex (pictex), pdf, jpeg, tiff,
+png, bmp, svg and wmf (windows only).}
 
-\item{path}{path to save plot to (if you just want to set path and not
-filename)}
+\item{path}{Path to save plot to (combined with filename).}
 
-\item{scale}{scaling factor}
+\item{scale}{Multiplicative scaling factor.}
 
-\item{width}{width (defaults to the width of current plotting window)}
+\item{width,height}{Plot dimensions, defaults to size of current graphics
+device.}
 
-\item{height}{height (defaults to the height of current plotting window)}
+\item{units}{Units for width and height when specified explicitly (in, cm,
+or mm)}
 
-\item{units}{units for width and height when either one is explicitly specified (in, cm, or mm)}
+\item{dpi}{Resolution used for raster outputs.}
 
-\item{dpi}{dpi to use for raster graphics}
-
-\item{limitsize}{when \code{TRUE} (the default), \code{ggsave} will not
+\item{limitsize}{When \code{TRUE} (the default), \code{ggsave} will not
 save images larger than 50x50 inches, to prevent the common error of
 specifying dimensions in pixels.}
 
-\item{...}{other arguments passed to graphics device}
+\item{...}{Other arguments passed on to graphics device}
 }
 \description{
-ggsave is a convenient function for saving a plot.  It defaults to
-saving the last plot that you displayed, and for a default size uses
-the size of the current graphics device.  It also guesses the type of
-graphics device from the extension.  This means the only argument you
-need to supply is the filename.
-}
-\details{
-\code{ggsave} currently recognises the extensions eps/ps, tex (pictex),
-pdf, jpeg, tiff, png, bmp, svg and wmf (windows only).
+\code{ggsave()} is a convenient function for saving a plot. It defaults to
+saving the last plot that you displayed, using the size of the current
+graphics device. It also guesses the type of graphics device from the
+extension.
 }
 \examples{
 \dontrun{
-ratings <- ggplot(movies, aes(rating)) +
-  geom_histogram()
-ggplot(movies, aes(length)) +
-  geom_histogram()
-ggsave("length-hist.pdf")
-ggsave("length-hist.png")
-ggsave("ratings.pdf", ratings)
-ggsave("ratings.pdf", ratings, width=4, height=4)
-# make twice as big as on screen
-ggsave("ratings.pdf", ratings, scale=2)
+ggplot(movies, aes(rating)) + geom_histogram(binwidth = 0.1)
+
+ggsave("ratings.pdf")
+ggsave("ratings.pdf")
+
+ggsave("ratings.pdf", width = 4, height = 4)
+ggsave("ratings.pdf", width = 20, height = 20, units = "cm")
+
+unlink("ratings.pdf")
+unlink("ratings.png")
 }
 }