Check out this very interesting project - re-routing an old gameboy's video signal to an oscilloscope. Just watch the
video.
There's a really great tutorial on how to do it yourself
here. It's interesting how hacking/technological interest tends to lag so far behind technological progress - the gameboy has been out for a long time, but only now are we messing with the vide signal. I think it's because when the technology is "new", the only people who fully understand it are those designing the products...
-Colin