A jQuery plugin to dim the current page once the top of a specific element has crossed the halfway point of the viewport
OPTIONS (and defaults):
How long it takes (in milliseconds) to fade overlay in/out
How opaque the overlay will be
The z-index of the overlay
Make sure to set the z-index of any element you'd like to appear on top of the overlay.
Developed by Stephen Widom - http://stephenwidom.com