Join the official Rockstar Games Steam group and get a free copy of Midnight Club II
From the Rockstar games Steam blog:
Join the Official Rockstar Games Community on Steam at http://steamcommunity.com/games/rockstargames by 10 am Pacific Time on Tuesday, May 15, 2012, and receive one non-giftable copy of Midnight Club 2 in your Steam account by May 29th.Eligibility: User must have an account with at least one successful purchase, gift or retail registration in the account. This offer is not available to users who already own Midnight Club 2.
According to the game page it's not compatible with Windows 7 or Vista, but from what I've read from people who already own it, it works fine.
Deadline is May 15th 2012, and you must already own one game.