I recently looked up the walking stick favored in Colin Fletchers new Complete Walker IV. It has a removable Vee shaped rest to convert the stick to a rifle rest. See it here
Stoney Point .<br>These folks also make crossed shooting sticks and other sticks.<br><br>I am not sure you want the high tech approach but this place also sells a tree saw attachment! With the camera mount screw in the top you can just about make anything to attach and change the function of the stick.<br><br>If you are going to make your own stick, you may want to consider placing a 1/4" x 20 bolt in the top to use as an attachment point for various other things.<br><br>and since you did not ask....

.......<br>My absolute favorite Walking Stick is made from the center rib of a Palm Frond. It is light, the frond is bamboo-like but solid wood, not hollow. It has absolutely no attachment capability or multi-function use. Just pure pleasure to walk with. I added a copper foot to prevent wear and a braided leather wrist loop.<br><br>