My mother has a the 30-inch LED Cinema Display, which is a bit too large for her everyday use. She prefers to use it in 1680x1050 or 1600x1200 modes, and can then switch to 1920x1080 for watching movies (Netflix, etc).
This switching is easily accomplished by Retina DisplayMenu, which lives in the menubar. The problem is that there are lots of different resolutions listed there, and she has a hard time remembering which ones are the right ones. I have previously created two AppleScripts, which I bundled into applications, that use GUI commands to switch resolutions; these can be run from Spotlight.
I'm thinking it would be neat to run at least the "movie mode" script when certain websites (e.g. Netflix) load. Is there any way (besides a constantly running script that polls each browser page for its URL) to trigger a script when a specific page is loaded?