Broken Telephone

The children sit in a circle. The teacher makes up a message that is long enough for the age group (i.e. younger kids can handle one or two words while older ones a sentence). For example, a cow goes moo.
The teacher tells this message to one child who passes the message onto the next child and so on until the message goes around the circle. Have the last person to get the message to tell everyone what the message was. Usually the person receiving the last message gets a totally different message at the end.