From bergdesign:

SuperCal™ is a visual display calibrator capable of measuring and correcting most conventional displays, including LCDs, CRTs and projectors. SuperCal doesn’t require any hardware measurement devices – only your eyeballs – yet it can be much more accurate, based on how well you pay attention to what you’re doing.

Highly usable software calibration app that gets a long due (Universal) alpha update. If you are serious about your display (no excuse for photographers), this one’s a must-have.