For shooting I use sticks and lean up against something for back support. Works great when a backrest is available, and to a lesser degree but still good when not. Weigh a few ounces.
Sticks are my first pick, fast and easy to use in the field. Sticks control windage and elevation, and even with a back rest, I usually pull a knee up to support the back end. In effect this constitutes a wide-base tripod.
