Something teaching or office-related personalized with their name
A desktop calendar/appointment reminder
Has he ever mentioned something he collects or a type of music he likes, a favorite sport, etc. There are always little things pertaining to those that make great gifts. I had a teacher once who love Garfield. He quoted Garfield. He had Garfield comics on his bulletin board, etc. He was also into politics. I got him a Garfield pencil holder personalized with: Neither republican nor democrat, I'm just an independent party cat. He loved it.