Input Needed: Gifts for Teens

I am getting ready to get prizes for our teen summer reading program. I have $100 for our "grand prize". In the past, we have given iPod shuffles for the big prizes, but I don't know if they are still "in" enough to be a good teen prize. So, I would love your suggestions for cool things teens would like as prizes in the $50 to $100 range. Thanks so much! Looking forward to hearing from you!