Rockstar Games is giving away a free copy of their highly rated 2003 racing game, Midnight Club 2 to those who join their official Steam group before May 15, 2012.
It is normally sold for $9.99 and has a Metascore of 81/100.
Details inside this post.
As the image above shows, this does not apply to those who don't have a paid game in their account or to those who already own the title. The game will automatically appear in the libraries of eligible people by May 29.
According to its Steam page, this game is not supported on computers running Windows Vista and up. So don't get very excited. There is a whole patching community online of course and some simple Googling will return to you several patches for the game that allegedly allow you to play it on Windows Vista or 7. I have no experience with them; I'll just try out whatever I can and write a post here if I am able to run it.
Rockstar's official Steam group can be found here.