The guys over at SuperHouse have really done their research. In the video, they explore just about every option you have for powering your network cameras. From the obvious, to the not-so-obvious. I’ve seen hacks before, and done myself, which is simply use the unused pair of wires to basically ‘extend’ your power adapter on a high amperage bus, then split again back at the camera. But what I haven’t tried is using a real POE injector, then using a small 5v switching regulator at the base. The beauty of doing it this way, is you avoid the dropout you are going to occur by simply running 5v on the other pair especially over long distances. In the video most of the time is spent doing this option, which is really neat because basically they take a really cheap foscam ip camera and essentially turn it into a more POE camera.
Another really green idea would be to cut the wires completely, and I do mean all of them. Use a solar cell, and a battery and power your WIFI camera from that. You would obviously need to be in a place where you could get ample sunshine during the day to charge the battery for nighttime use, but the concept is solid.