Begin by having everyone choose a new name. Make name tags for everyone with these new names. They will be like strangers, and they can talk about anything they want, just as long as they do it under their new identities. Follow up with a discussion of the experience. You can get a lot of mileage out of this, and it really helps young people learn some surprising things about themselves.
Most kids love to get something in the mail when they are away at camp.
It can be quite disappointing for campers when they hope they will get something, but nothing ever comes. To remedy this, secretly contact all the parents of the campers in advance, and ask them to prepare a surprise package for their child. These can be collected without the kids knowing anything about them, and then, during this small-group time, they can all be handed out at once. The kids will freak out. You might want to specify to the parents the type of things that will work best in the package, but let each parent give whatever he or she wants.