As you can see from my demonstration video below, hand-jerk when using a handheld camera is a problem for many people.
I am working on building a DIY Camera Stablizer (commercially known as a Steadicam). Here is one Scotsman, Wsclater, with his implementation and some working designs on his website. This gentleman's demonstration is what inspired me to get started on my own.
His rig in action:
Search YouTube for "DIY Steadicam" and you will find some working examples of other people's work. But so far finding a sufficient curved boom to mount the camera and counter-weights has been a challenge, but I have found tonight that using a chopped up Aluminum tennis racket frame may do the trick as it is already pre-drilled, rigid and should be easy to adjust. (Will post a picture of tonight's cuts after finding a camera)