glTron for OS X

For a good example of the performance of OS X's OpenGL system (and if you like a good game) check out glTron for OS X. Originally a Linux title, this is the most fun and unique game I have found out there that runs natively under OS X. Most everyone's seen the mid-80's Tron arcade game which features the overhead light-cycle race. This takes the light-cycle experience to a new level, providing a variety of views of your 3D racer in its 3D world--good stuff. Great performance even on mid-range G3's. (Apple's OpenGL implementation under OS X is pretty sweet.)