There is an inherent tension between "cooperation" and "competition" in strategic games, and even more so in the presence of private information. Real-world players often circumvent this difficulty by cooperating through agreements and side payments. But which agreement should be made, and how can it be made in an incentive compatible manner? This talk will present a general solution and applications to (a) routing and (b) selling hot dogs, with private information. No prior exposure to game theory is assumed. This is joint work with Ehud Kalai.