The camera operator may walk (or even jog), move through tight hallways and doorways, and even climb up and down stairs without shaking the camera. Unfortunately, professional steadycams cost around $1500. Even the cheap 3rd party ones cost $600+. Whether you are an aspiring filmmaker, a videographer, the family documentarian, or just want more utility out of your video camera, you'll appreciate a steadycam. Includes Video of steadycam working.
http://www-2.cs.cmu.edu/~johnny/steadycam/