I like the memory idea. that's a really ccol idea. way better than any single present i can buy. As for his interests, he's kind of a zero - i suppose it goes with mathematical/physicists types.
He travels around the world a lot to different space agencies and meetings on earth science stuff. I dont claim to totally understand what exactly he does. I do law, he does science - different ends of the spectrum.
But as for a memory? hmmmmm. I'd have to think about that one. but thanks for the ideas, peeps.