I believe there are some models of Canon dSLR cameras that do not work with the tethered on screen live view (not 100% sure about that but I think that is what I remember someone saying) and this is a definite step above using the timer in my opinion. Liveview does work with my camera as long as I have it tethered to a computer which can be a pain since my desk is usually cluttered beyond belief. I used the little one I made first in the link above so much the button stopped popping back up after it was pressed and started being a hit and miss type of thing on if it wanted to work or not. This one should work for years and its not hard wired to the canon size cable so if I want to use the button with something else all I have to do is put the 2.5 jack on the end of what ever type of wire I am using elsewhere and use the push button for that also, that is why I put the stereo jack panel mount in the end instead of hard wiring the push button to the wire.
Edit I noticed the link above didn't take you directly to the pictures of the switch so I fixed the link but this is a picture of the first switch I built which was just a simple cellphone microphone and headphones that I modified to work as a remote shutter switch. The wire was a little to short for my taste though
