Hi Heidi--
I offer the gift certificate route. The image in
this link is outdated. . .I think now I would put it in one of those nice little black boxes that someone recently posted. . . But anyhow, it's something that can be wrapped and opened as a gift and provides the recipient with the opportunity to be involved in generating reference material, for instance. (Sometimes when people are trying to surprise someone, the reference side of things can be, well, tricky at best.)