[Update: It looks like Sony caught wind of what was going on and has temporarily removed the game to prevent folks from loading up on free Uncharted. It was fun while it lasted.]
Uncharted 3: Drake's Deception's single-player campaign is presently available free of charge for those with a United States PSN account. That's right, you don't even need a PS Plus subscription to get in on the action.
The solo portion Naughty Dog's action-adventure title has been offered as a Plus reward in the past, and the multiplayer component went free-to-play over a year ago. Still, this is a great opportunity to check out the game if you haven't already.