Straight off the front page of
Slashdot this morning...a do-it-yourself Steadicam® for about $14 and twenty minutes of time.
I've never seen a real Steadicam, let alone used one, so take it for what it's worth.
http://www-2.cs.cmu.edu/~johnny/steadycam/
The site has step by step construction instructions and sample video.
Mike