(http://i.imgur.com/6TfdY5o.png)
Steam has announced a beta version of game sharing (http://store.steampowered.com/sharing) that will allow users to share their game library with up to ten family and friends. A feature that was originally announced (http://www.ign.com/articles/2013/08/09/this-is-how-xbox-ones-game-and-gold-sharing-works) on the "XBone 1", but then removed (http://www.polygon.com/2013/6/19/4446308/xbox-one-family-sharing-plan-cloud-library-price-cut-plans) as part of dealing with DRM has been picked up by the GabeN army.
Currently you need to request access, and there are limitations. You can't share the game as in you both play it at once, but a friend can play a game while you play something else. As the primary account holder you would take priority. So if a friend is playing your copy of Payday 2, and you want to play, it will prompt the other user to buy the game and give them a couple minutes before the game shuts down.
It doesn't appear to have the option (yet) to allow you both to play the game together at the same time.
People here tend to have the same games already, but we could start up a FITES sharing pool. What are some thoughts? Does anyone want to take a stab at game sharing?