I'm not sure exactly which infrared remote model number is used on the Canon T2i / 550D, but for the Canon 5D Mark II you would use the RC-1 infrared remote. This is a nice handy little remote to shoot photos and also start and stop video. The problem is that it's infrared and you'll need to get the remote somewhat in front of the camera to trigger. A tethered remote is nice, but that has some limitations also, especially not being able to start and stop video (only the infrared remotes can start and stop video on the canon DSLR).
Here's an unusual remote that just surfaced offering both a cord type connection and offers an infrared trigger too. Now if your only concern is to get a corded remote, i'd go straight to the Intervalometer I blogged about not too long ago. But to start and stop video, you definitely need to trigger it via Infrared so you'll have to get a second remote.
Using this item here, you get the best of both worlds "ONLY IF THIS CAN START / STOP VIDEO". There's no mention that it can actually do video, but having infrared built in, i'm guessing it already does. (no timelapse options). It's very early with no information out on this thing, but check it out if you're bored.
If you're shopping for a remote simply to do photos, here's a similar setup as to the Wireless remote I did a demo with on my Canon 5D Mark II. (See the Demo Here) This is both a corded remote as well as a Wireless Remote option for photography. It cannot start and stop video, but the wireless works much better since it doesn't rely on Infrared. check out the dual Corded + Wireless remote for the Canon T2i / 550D.