https://www.facebook.com/logitechgaming?sk=app_214211995267353&app_data=dlt-1

Just fill out the information there and receive your free key

Just go to the Metro(THQ) facebook page, "Like their Page" and click on the free download button. A screen will show with a "reveal key" to show you your steam product key.

Here is a quick video i found on forums showing you how to do it.
http://www.youtube.com/watch?v=D4rHDJjBMuw&feature=youtu.be

I already tried it and it 100% works so enjoy!

https://www.facebook.com/home.php#!/MetroVideoGame?fref=ts

Yes it is free for 1 week and once you have it in your library its your to keep forever ~

Good till Nov.8. 2012

http://www.steamgifts.com/giveaway/70s9d/turba


There are 1,000 keys being given out in steamgifts right now by the developer so get in while you can! Chances of you winning a key are very high so you might as well try. Goodluck~

http://www.reddit.com/r/gaming/comments/ve7dj/my_indie_studio_is_giving_away_4000_free_copies/

Send a message to "retrovirusgiveaway" asking nicely for a key and you will receive it as long as they still have some. (reddit account must be a day old)

Enjoy~