I have one for my Canon 400D. In theory it's to take photographs of the birds on our birdtable. I set the camera up outside the kitchen window on the tripod and post the remote through the window. Great in theory but the blighters seem to realise I want them to perform and they all fly off
It is really good though and didn't cost too much.
I have one for my Canon XTi, just got it a few weeks ago. It was only about $20 through Amazon and it works great, oh and it's a tiny little thing I'm afraid I'm going to lose it lol!
I have one for my Canon Rebel xTi and it works great. I just took pics of the kids and I for Father's Day using it and I loved it. Shawna is right though, it is SMALL, LOL!