Color Blindness Simulator
If you design web sites and use a Mac, you must check out Sim Daltonism. It’s a small little application that allows you to preview your work as a person with color blindness would see it. The program lets you choose between 8 filters of the four types of color blindness.



One word: insane! (Thanks for sharing, by the way!!)
There is a website that offers similar functionality
http://www.vischeck.com/