Positive Reinforcement Cards Game
Whenever a participant arrives to class on time from breaks, lunch, etc. give them one playing card. You can also hand out cards to people who volunteer for activities, are helpful, answers a difficult question, etc.At the end of the day, play one hand of poker. Give a small prize to the best hand (you can also pick the top two or three hands if you want to give away more prizes). Note that the more cards a person has, the better the chance of winning.
Human Bingo Game
Before the meeting, make a bingo matrix and at the top of each square put something that someone in the group might have done-for example, voted for Ross Perot, served in the Peace Corps, etc. Everyone gets a copy and is asked to circulate, getting other group members to sign one square that is true of them. The first person to get "bingo" wins the prize (a candy bar or some other small thing).