Of course, my 1Ds2 can't accept an ordinary inexpensive mechanical (read reliable) cable release. No, it has to use a Canon made, expensive (prob. 8 X the price of a mechanical cable release) which is highly unreliable and so far seems to have a lifespan of six to nine months shooting (or considerably less). The other day when my third such release failed, I had to switch to my even more expensive release with the intervalometer (purchased before a trip when they were out of ordinary ones). OF course it's so long it falls on the ground and gets dirty, the lcd screen on the release gets stood on and scratched, and the whole damn thing gets wrapped round the tripod and head and camera in ways you wouldn't think possible.
Anyway, this time when I went to pick up a replacement, I was offered a third party release for significantly less, OR, I could purchase a radio release for twice as much. I splurged for the radio release on the grounds that I'd not have to deal with long cords and the pull on the plug (which is I suspect the area of difficulty for the normal ones). I'll let you know how it works out. So far the first obvious thing is that since it sits on the hot shoe, it has to come off when the camera goes in the bag, but I think that will be manageable. I'll clip the actual release to my clothes so it doesn't get lost (it comes with a clip and a hokey chain which I immediately replaced with a better one I had lying around.
Both the receiver and remote are small, the plug looks solid, but time will tell.
The release is made by RFN and certainly works in tests and can even handle B shutter speeds and partial presses for focusing. Here's hoping.