DIY: Nikon IR remote in a Lego
This project requires a little more skill then most; you have to be able to manufacture a PCB and program a microcontroller. This could be problematic if you don’t already have the necessary gear, so that $40 might not seem such a bad idea. The person who created this project on Instructables did a far better job explaining it then I can, so head on over there and check it out. I’d do one myself, but my camera doesn’t support IR.