Gift ideas for my friend's boyfriend's 21st?

A shirt and a card. Or a cake and a card. You don't have to go all out. You could get him a gift certificate to a music store so he could buy a CD. Nothing too fancy. Buy him a drink at the bar too and wear something nice. He'll just enjoy your company. Or you could take some photos of his 21st and make him a little album. Not a scrapbook, just a simple 3x5 album with the pics in it.