I got my raspberry pi in the mail a few weeks ago. My plan is to eventually build a MAME arcade, complete with authentic arcade controls and a working coin acceptor (just dumps the coin in a tray so you can use them again, it's mostly there for fun and because I can do it).

The raspberry pi is a credit card sized computer with an 800MHz ARM processor, 256MB of RAM, and runs linux.

Raspberry pi surrounded by junk, it's the green thing next to my multimeter. The thing with three wires coming out of it is a coin acceptor. The blue thing with a computer chip is an arduino uno mounted on a plexiglass board along with a half size breadboard.
Note that I don't actually keep the raspberry pi exposed like that when it's in use. I haven't ordered a case for it yet but when I use it I have a plastic sandwhich container I cut apart that it sits in to provide basic esd protection or from accidentally shorting on random metal.

I'm still waiting on my radio tuner to come in from deal extreme so I can try making it into a software defined radio. I might need to overclock the pi but even at 900MHz I don't know if it will be able to demodulate a radio signal at any reasonable speed. I'm not too worried though since I can still use it with my laptop running SDR#. I've put off working on my pi for a bit until I can move all my stuff over to an electronics lab at my university. Working on a dinner table in my apartment just kind of sucks.