Oh thank Science! I always look for this program whenever this debate starts every few months. I keep forgetting what it's called or where to find it.He designed a split screen program that lets you sample 2 different FPS rates. Pretty neat for proving to ppl that you can tell the difference >30fps.
http://www.tweakguides.com/files/FPSCompare_v05_beta.zip
Everyone please get this 11kb application from here:
http://www.tweakguides.com/Graphics_5.html
It's the simplest and best way to see for yourself that eyes definitely need more fps in games without motion blur. Another way to test that is to play an FPS game at 30 fps and move your mouse in a circular fashion...Your view will seem jumpy as hell if you don't have 60 fps or more so your eyes definitely notice it.