Need help picking out a graduation gift!

I'm stuck. A good friend of mine is graduating with his PhD in lasers/sound. He's probably the smartest person I know. He's also from Germany and a bit of a Euro-snob. He's also a big gun nut and loves anything military- at one point he was trying to build a scale tank that shot real bullets. We played rugby together and he was a party animal at one point, but he's since settled down and is getting married soon to a medical doctor.

I'd like to get him something that is memorable, geeky, and lasting. His graduation is this weekend, but if the gift is late, he will understand.

Any ideas?

 

He also likes gadgets and spy stuff like those tiny cameras you can hide anywhere. And he makes his own jewelry, too.

I'd like to keep it at or under $100. I've been looking at thinkgeek.com but nothing jumps out at me yet.

 

I figured it out- I'm going to get him ordained as a minister for the Universal Life Church.