My usual backpacking photography kit consists of my 5oz camera and my 1.5oz gorillapod. I recently acquired a smaller camera (the 2.9oz Samsung ST30) and I have been looking for a lighter alternative to the gorillapod.
I had an old mini-tripod, so I dissected it for the mounting screw and ball joint. The mounting screw is aluminum, and the socket component of the ball joint looks like nylon. I drilled a hole in a SmartWater bottle cap, pushed the ball-joint into the opening (it snapped in nicely) and secured it with methacrylate glue.
I failed to weigh the unmodified cap beforehand, but the modified cap weighs 4 grams. The platypus cap next to it in the photo below weighs 6 grams.
It is very stable with the camera attached, despite the position of the mounting point on the camera. The ball joint allows the camera to be pointed up or down or swivelled around.
I inverted the bottle and squeezed it hard and the modified cap doesn't appear to leak.