Steam Punk Star Wars The first two (by date) are especially cool.
It's Raining 300 Men A very silly (and unfortunately rather short) music video combining the obvious song and the obvious movie. It doesn't really make me feel any more inclined to go see the movie, but it's still amusing :)
Transformers movie trailer 01
Transformers movie trailer 02
Transformers movie trailer 03
JSettlers A java version of Settlers of Catan that you can play on the web. I normally play against the AI but you can play against other people.
Some Firefly stuff: A map of the system and a pdf of "blueprints" for Serenity
And speaking of maps, here's a map of the most generic country ever, and there are a lot of other very random maps on that site.