I have been involved with a few volleyball camps and clubs in recent years. I find that a good ice breaker is to bring a bag of candy, and have each of the participants grab a few pieces. After each person has grabbed some candy, have them stand up, give their name, and for each piece of candy that they grabbed, they must say one thing about themselves. Of course, you will get some who will grab a handful of candy, and others who do not want any. Also, try to use hard candy as there are quite a few who will not or cannot eat chocolate!