Remember that funky beat your buddy at work shared with you over Google+? Don't bother digging through their post history, Mountain View's music service has you covered with its new "Shared with me" auto-playlist. This self-maintaining list keeps track of all the songs friends and colleagues send your way, making it easy to hunt down a catchy tune your brother sent you, or to endlessly ridicule a coworker's awful sense of sound. The playlist not only shows the track, artist, duration and price, but also a preview of the Google+ post (and a thumbnail of its author) that you scored the shared song from in the first place. Looking for lost music? Just take a look at your auto-playlists.