We have a lockin the day after Thanksgiving. It was started as a benefit for the parents who wanted to go Christmas shopping on 'Black Friday,' plus it is kind of a fun thing for the kids since they have school vacation and they get to spend the night at the gym. They can bring friends, we have TV's, DVD's, playstations (E rated games only) etc. We have pizza and snacks. They have to sign up before hand and prepay. I can't remember the price, but we just had a pool party at the Holiday Inn with pizza and ice cream and that was $15/kid. The adult students help chaperone. It is a blast!!
The main objective is for the kids to have fun and in the case of the Thanksgiving lockin to give the parents a safe place for the kids to go have fun while they do some shopping or whatever.