That's a great remote, and I love it, but unfortunately, it only works with XXXD bodies, the 5DMkII, and the 7D. If you have a Canon body, if the grip doesn't have a little greyish dot on it, you can't use the RC-1/RC-5; there's no infrared sensor in the camera to receive the signal.
The other drawback to the RC-1 or RC-5, is that it's using infrared. Line of sight (just like with a television remote) is required, and the range is relatively limited, particularly outdoors in bright sunshine. Secondly, it's far easier to use from in front of the camera (say, for self portraits), then from behind the camera. It can be done, but given the placement of the sensor on the front of the grip, it can be a little awkward. If you plan to work primarily behind the camera, a cable release might be a better choice. And, of course, you can always use the timer.
Radio triggers will overcome the range and line-of-sight issues, but you have to have an external receiver unit on the camera, as well as the transmitter. The advantage to the RC-1 is how tiny it is, and how it sits on the camera strap, so that it's
always with you, and that the receiver is built into the camera. Essentially, you don't have to find a way to pack it in your bag.
