Using this I built my own remote shutter trigger this evening. I found a Body Glove Earglove Sport at Walmart for $10, sadly every Dollar store I tried didn’t have any wired mobile phone headsets, Big Lots was no help either. As per instructions I did have to remove the microphone, but honestly the hardest part of the whole thing was getting into the housing the contained the button and the mic. I tested it with about 15 shots in different modes with my Canon T1i and it works great.
The one drawback is that the button doesn’t depress half-way so you can’t enage focus lock without also engaging the shutter. My plan to counter act that is to compose and focus beforehand then switch to MF to prevent AF from refocusing unintentionally, if anyone has any additional ideas leave them in the comments.