Looks like the Humble Store is giving away some free games every Monday until September 22.
https://www.humblebundle.com/store
September 8 - Warlock: Master of the Arcane - https://www.youtube.com/watch?v=0ydHz7X4GF8
September 15 - Receiver - http://www.youtube.com/watch?v=IEFF3kYnbdg
Settember 22 - Tropico 3 - http://www.youtube.com/watch?v=9WJXX2IOzxE