After the recent success we had picking up the Just Cause 2 Gift Pack, I decided to start a Steam Group dedicated to things like this. For Giant Bomb users only!
Edit: Group is now public. Feel free to trade and get pools going for group deals, just make sure you know who it is you're sending games and/or money to!
I'm always happy to middle any group buys by holding PayPal funds and then distributing games, even if I'm not interested in whatever is being purchased at the time. Just send me a PM here on the forums and we can work it out.