This hard to find gadget is a life-saver!
I probably wouldn't bother to use a glidecam at wedding shoots if it weren't for the ease of use this device allows.

It comes with and accepts release plates made for Monfrotto series 501 & 503 heads. Has the same lever type and safety button that those heads have. Simply screw this adapter onto your Glidecam or shoulder mount and leave it there. From that point on, moving your video camera from tripod to Glidecam, etc. is fast, safe and simple.
You can find this on bhphotovideo.com by searching part # BO577 or on ebay at -
http://stores.ebay.com/cine-city(Note: image is from the ebay store and it looks a little different from the B&H item, especially not showing the lever that tightens the plate.