ggflags

flag geom for ggplot2

library(ggflags)

set.seed(1234)
d <- data.frame(x=rnorm(50), y=rnorm(50), 
                country=sample(c("ar","fr", "nz", "gb", "es", "ca"), 50, TRUE), 
                stringsAsFactors = FALSE)
ggplot(d, aes(x=x, y=y, country=country, size=x)) + 
  geom_flag() + 
  scale_country() +
  scale_size(range = c(0, 15))

The flag SVG assets, used under the CC-BY licence, are taken from the EmojiOne set: https://github.com/eosrei/emojione-color-font

(Note: the EmojiOne set doesn't include UK counties or US states!)

(note: proof of principle only)