While surfing around tonight I found FFR(Flash Flash Revolution). It really tests your keyboard dexterity. Though I would bet most people use the site with a gamepad of some type. It is pretty interesting to try it just using the keyboard.

I am not that great at it. Though eventually I could get better. I also haven't really played DDR at all, though I did try a little bit this past summer. I know its something I wouldn't mind getting into at some point. One really just needs to take the time to get used to the game which I haven't yet had the chance to do.

FFR gives you half a mental workout at the least. Still nothing compared to real DDR.