It has been months since I've posted....ouch. I've been playing around with a camera stabiliser for the Canon 550D. Initially it didn't work very well. I discovered that the 550 was simply too light for the stabiliser. After adding some extra weight to the camera end of things, it seems to perform much better.
This is the stabiliser I ended up buying:
http://www.b-hague.co.uk/hague_dslr_motion_cam_camera_steadicam_stabilizer.htm