Indie Gala are giving away free Steam keys to Afterfall: Insanity
^That's a link.
After inserting a valid email address, you need to join the Indie Gala Steam group and verify a Captcha. Haven't tried it because I already have Afterfall: Insanity
Also, if you spend at least $10 in their store you get a free copy of Afterfall Reconquest Episode 1.