Gather the teens in a circle, unwind a length of string or yarn around the inside of the circle (with everyone holding the string taught). Before breaking the string and tying it to form a circle, place a cheap ring on the string. The ring will then be on this loop, and teens will attempt to pass the ring from one person to another—without these exchanges being noticed by one person in the middle of the circle. It is best to do a five-count before beginning each round. This is a fun and energetic game that also can be played on a bus or in a small room.