I bought the Orange Box via Steam yesterday. I already had Half Life 2, so, I have a gift pass for Half Life 2 to send to someone with a steam account (which you can get for free). To make it a but more fun, I've written a number down (Between 0 and 10,000). The person who posts the number closest to it will win the game! You can obviously only post once.
This competition closes at 23.30 (On my clock, it's 23.08 now!)
Good luck :D