I think a tee is a good idea, he's always moaning about the state of his own...
Well, if that's not a hint that he wants new threads, I don't know what is! Threadless.com is good for cool printed tees. I've also done my own prints in the past, with stencils and textile paint, it's a little fiddly, but they turn out great and they will be completely unique!
Good luck and congrats on the 2 years!