Neat little colourblindness simulator for OSX

Just got an URL from a friend that is too good to be kept just in my private stash: Sim Daltonism is a real-time colourblindness simulation app for Mac OsX. You can select what type of colourblindness you’ll like to simulate and a small window shows the area around the mousepointer with this filter enabled. This little gem might save Vischeck.com some traffic and us less time spent copying+pasting into Photoshop (and checking with the Vischeck plugin).