I saw a poster on TIGSource talk about manually cutting up sprite sheets, so I've dusted off a project from 2007 to solve it. Just load up a sprite sheet, select the background color, and export the results into a directory. It's got a few extra features useful for what I originally wanted it for, too.

Announcing my newest finished project, Box2DWith. I'm collecting together various utility classes for doing all the stuff with Box2DFlashAS3, but found annoying. Demo, Docs