I am surprised not to see this video on the list.

http://www.youtube.com/watch?v=T7TI-AJi2O8

Lip syncing, long one-taker and all done in reverse!

Actually, I read somewhere that it is actually a mild form of epilepsy triggered by touching the very sensitive behind. I always feel really bad for these poor cats that have this problem because it looks to me like they are in pain but can't properly express it. It makes me sad...