For general feedback about the game.Steam Support
Visit the support site for any issues you may be having with the game or Steam.
Some of the Steam folks dropped by the TF offices this morning with some interesting news: They've just shipped a new feature they're calling Trade Offers. It's similar to regular trading, except you can propose which items will get traded. Whoever you're trading with can then choose to accept or decline your offer, or make a potentially interesting counter-offer.
The best part is, you don't even both have to be online at the same time now. You can make trades while you sleep! While you're having dinner! Even while you're going to the bathroom. All cards on the table here, pretty much the entire blog post up until this sentence was a preamble to us getting to tell you that you can trade TF items while going to the bathroom. Move over, reading a magazine! Take a hike, preparing dinner!
Anyway, check out the Steam Blog post for more information or start sending offers.