I am forever losing that little dohickey that connects the camera to the tripod. Maybe if I had a really nice tripod I'd take better care of it? Or more likely, I'd be out the piece to a really expensive tripod instead of to a cheap one...
I leave mine on the camer all the time, but for my back-up tripod I use a rubberband to attach the quick release plate to the tripod head so the two are always together. :)
mine is always attached to my cam. then again i only use a point and shoot cam. with the SLR i want to get i think i would most likely put it on and take it off according to my needs...i also have a cheap tripod