fun online game I found, there's 3 in the series the third one being insanely harder than the last 2

Super Crazy Guitar Maniac 3

My favorite song on there so far is the instrumental song by DTG

Much better guitar hero-esque game here:

http://www.addictinggames.com/guitarmasters.html

Get to hold your keyboard like a guitar etc.

I guess this would be better with speakers, right