Today I wanted to do some long-time exposures. Since I can only choose exposure times of up to 30 seconds, I have to use the so called “bulb” mode, which just exposes as long is I keep the button pressed. I can not hold perfectly still for tens (or tons) of minutes, so I usedTutorial (german) as an inspiration and built my own remote release trigger using a small wood piece as a base, a button and a switch, a cable with a 2.5mm jack I got from an infrared receiver and loads of hot glue to make it comfortable to hold. Have a look.
This should also fit for most other cameras of the Canon EOS series, but there are some exceptions.