Will remote shutter releases stop and start video?
I don't know much about physical trigger devices, so not sure if starting/stopping a video is possible with those.

However, you can use a "software" trigger that is included in the modified Magic Lantern firmware that is available for free for several Canon cameras (including the 550D).

After you install the ML firmware on an SD card you will have access to many video recording enhancements, so it might be helpful in general.
According to the manual you can trigger the start/stop of a video (or take a photo) by using the LCD sensor or the built-in microphone.
From experience I know that the audio trigger is more reliable than the LCD sensor, but it requires that you set the trigger volume threshold according to the sounds in the environment.

Here's more information on the risks of using the custom firmware, and here's 
the Magic Lantern installation guide.