We're seeing lots of new faces / less than regular faces popping up and putting out amazing work, so you owe it to yourself to join our illustrious level design community and revel in the virtual camaraderie of a lifetime. (... But don't go into EOT. Don't don't don't go into EOT.)
Here's some stuff being thrown around in the WIP thread. (Note: I did not make any of these levels)...
Look at all this raw creativity oozing out of your monitor right now. Can you feel it? Can you smell it? Yes, it's urine -- but it's the urine of joy.
So if you know how to use Hammer, Radiant or UnrealEd, just whip up a crazy-looking 20 brush map and throw-in! You won't regret it. And it probably won't take you too long either.