You could get him a minimalist wallet, a key chain or ring, a sweater, a football jersey, a pair of cufflinks, a zipboard, or a collectible sport ball. You could use gifts.com to help you choose a nice gift depending on his personality.
30 different things he likes! This will work for any age, until you get to like, ummm, 65, 55, you may start to really think ha! ha! ha! but really, does he/she like coffee in bed? does he/she like strawberries, like cookies in their lunch?, like Hershey's kisses?, you see, one of each of something they like make 30! Yippeee!!! You can take it from here.. I'm sure of it!