Here is a 2nd IR remote control that I modified to trigger the video recording mode of my Canon 550D (t2i). It should work for other Canon DSLRs as well. By positioning the trigger button near the right handle, it is easier to trigger video recording on and off without pressing the video record button on the Camera itself.
In my first prototype, I used a bigger remote, though it works very well, it turned out to be very bulky to secure to my DSLR rig. I ordered a slimmer model from ebay for around USD$3 which you can see from the photo below (the Jue Ying Model on the left).
You will need to get several items make this hack.
1. 2mm Plastic optic fibre ( I got this at a local electronics parts store)
2. Soft wrapping wire
3. Shrink Tubing ( slightly bigger than the diameter of the optic fibre)
5. Small Contact switch
7. Soldering Iron and Solder
8. Blue Foam
9. Fibre tape
10. Hot Glue, Various adhesive tapes
11. Pliers, Box Cutter and other tools
You can view the video to see the build process and how I secure it to my GINI rig.
For people with super soldering skills, you can de-solder the IR LED emitter and solder extension wires onto the ends (taking note of the polarity) and have the IR LED emitter placed as close to the receiver on the camera as possible. In this way, you don’t even need the optic fibre.