Check out gog.com while steam is down. Heroes of Might and Magic 3 is $5 - FTL $5 and bunch of other great games. Good times!
Seems like Steam is back online, I couldn't open the main page for a couple of hours. I got the game for free without any problems now. About GOG.com - I'm a BIG fan of the platform, I like it much better than Steam mainly because I'm a sucker for classic games, and it's DRM-free. The amount of fantastic games you can buy there is outstanding, and more great titles are on the way. I strongly recommend their holiday sales, you can get some really good deals buying the games in bundles.
License locked! Also of note Terraria is dirt cheap on there right now too. Not free, but only a couple bucks.