Share your computer?
Now share your games too.

Steam Family Sharing allows close friends and family members to play one another's games while earning their own Steam achievements and saving their own game progress to the Steam cloud. It's all enabled by authorizing a shared computer.

Is there a limit to the number of devices I can authorize to share my Library?

Yes. A Steam account may authorize Family Sharing on up to 10 devices at a given time.

http://store.steampowered.com/sharing/