This clever Flash game was passed around the webs a few weeks ago, but if you missed it then you should definitely give it a shot. It will confuse and stump you during your first playthrough, but stick with it--suddenly it will make sense, and you will be impressed.
Flash games can be great for delivering inventive gameplay mechanics in an easily-accessible package, but Nekogames' Cursor*10 goes a step further. It actually seems to create its own gameplay category: the single-player cooperative game.
I think it speaks volumes about my own inadequacy and self-defeating nature that can't even play games where I have to co-operate with myself.