Bill Cunningham

I really love laser-cutting. I do a lot of laser-cut jewelry and laser-etched stationery. I'll even etch my food sometimes. You can download an image online and etch it onto a tortilla or a brownie. It's so cool to meld the digital and analog worlds together.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.