See, you gotta do it right. Make it romantic. Stars are romantic. It has to be on a huge scale, too, so it sounds impressive. And then you need something tangible, so there has to be a piece of paper, preferably showing how they could see the thing named after them. Stars are easiest, but you could do custom constellations named after them. Shouldn't be too hard to hack up a python script that draws pictures over a star map and prints out certificates of the brand new constellation.

I'd buy that for my grandma. She'd like that.