I know this has been making the rounds lately, but WOW!  These folks drove a couple of player pianos and some percussion instruments with output from the score and sound effects of several Mario games.  I originally saw this on Gizmodo, but they got it from Geekologie.

I remember a guy in 8th grade band who had a Nintendo piano book.  I really wanted that book – especially for the Zelda songs.  This was pre-Internet (or at least before I had ever seen or heard of the Internet – I’m sure there were folks already using it at research institutions, etc), and I never was able to find a copy.  Just having the piano music for Nintendo games was so cool, but it never occurred to you could use a piano as an output device.