(Yes, I'm here for the contest too... annnd to suck in everyone's knowledge *grabs a straw* I actually got sucked in via the Amp Hour and watch a bunch of videos and subscribed, then saw the contest post this evening.)
What's under my keyboard is a drawer and half of a giant mouspad, what's IN my keyboard is anybody's guess. Probably ash and little bits of wire insulation, solder and dust bunnies.
My desk is my everything space, it's pretty big and lots going on. Circuits get built, contests get entered, things get ripped apart and repair and of course keyboards get trashed. I liked my backlit Logitechs and all, but finally I just broke down and buy a $15 Dell keyboard every year(KB212-B), it's much easier. I use them all the time at work so it's pretty natural to sit down at and use.