Twenty Questions IV
One player thinks of a person, place, or thing. The other players try to guess what he's thinking by asking him "yes" or "no" questions. If they can't figure out the name of the person, place, or thing, the first player wins. If someone does figure it out, she gets to think of something next. If a puzzle goes unattended for more than a week, send a reminder to the player. If it goes unattended for another week, assume it's dead and start a new one.