That reminds me of an approach that I use to reduce weight while backpacking. Specifically, you can carry a lighter tripod than you might if, after setting up the tripod you drape the shoulder slap of your camera bag over the tripod. This not only holds the tripod down, it stabilizes the tripod. Perhaps best of all, if the top of the camera bag is left open, all of your lenses and other gear are within arms reach -- with no need to bend.