If you have not discovered the joys of trekking poles, then you're missing out. When used properly trekking poles like the ones below can help take the pressure off of your back and knees on those all day shooting excursions. Aside from water your equipment can really weigh you down. Trekking poles will help you stay more upright, go uphill better, and take the pressure off your knees on the down hill. Even if you do not have back or knee problems, trekking poles will extend your endurance and allow you to stay on the trail longer.
Some trekking poles now come with a screw for your camera. Instead of mounting your camera directly on the pole, attach a small ball head. Please note that trekking poles are designed to take your entire body weight on the down hills while your monopod is only designed to take the weight of your camera. It's probably not advisable to use your monopod as a walking stick.