If you have a banking relationship with Citi, I'd suggest the Citi mtvU card. It gives you 5% cashback on restaurant (including fast food) spending and bookstore spending. I think you get points for having good grades too?

With a banking relationship you could redeem the points for fixed flights via ThankYou network. Otherwise you could also redeem for gift cards, etc.

This is assuming you pay off your balance each month because this card does have a pretty high interest rate.