Interesting I guess if one is into such stuff but I'd suggest putting your artistic talents into something a bit more constructive and most Mac users have their G4s almost buried under their desks and almost out of site.
But if you're like some of the non-Mac PC user crowd that seem to get into this sort of stuff, why not add some internal LEDs and some other internal flashing stuff or more into the G4 so it's not left out in the cold on its own and then show off all its possible abilities and blast away any PC showoff friends as to what the G4 can actually do??
Just a thought and I'm also a G4 MDD user with it under my desk and with a 24" Intel iMac on my desk, and no extra graphics added or flashing lights in either.
Works for me.