Facebook has confirmed that it has bought up Hot Potato, a startup behind a service that lets users communicate about activities they are doing at a given moment. On Hot Potato, users list what activity they are doing and then see others who are doing the same thing and can ask questions or share photos and videos with them. As with all of Facebook’s recent acquisitions (with the notable exception of its purchase of FriendFeed last summer), Facebook is shutting down the Hot Potato service; Hot Potato’s team, meanwhile, is moving over to Facebook.