Here's my take on the DIY camera remote/cable release. Total Cost: $0 (since I already have the switches).
All you need is a stereo sub-mini jack (3/32"), 2 switches, and a case of some sort. I used an old film canister as the case in keeping with the photography theme.
The side button functions as an "auto-focus" button and the top button functions as the "shoot" button. You hold the film canister like a joystick, using your finger and thumb for the buttons.
If you're interested, I have DIY instructions here...