The Westerville (OH) Public Library has wii and Xbox 360 set up in the library for patrons to use. The games are popular, of course, and often have a waiting list.
To improve the patron experience, their Friends group purchased a set of restaurant pagers (those disks with flashing lights and vibrations that alert people when their table is ready), which the library uses to let patrons know when it's their turn to play.
I thought this was a great idea. These pagers could also be used when patrons have to wait for computers or study rooms, or anything, really. They require staff time to manage, but they seem more efficient than a sign-up sheet, and they have the added benefit of letting patrons use the library while they're waiting, instead of being stuck in one spot.
Good job, Westerville.