bobw, the thing I want to avoid is extra cost and extra hassle. I'm not particularly fond of having 30 injectors all strapped to my ethernet switch, but I'm sure even that solution is more cost effective than running 110V power to each site. Not to mention the problem of running ethernet line parallel to power conduits. That doesn't work very swell due to interference.
If I go with a PoE solution, I have a good chance of reducing complexity and increasing flexibility (i.e., running a Cat5 cable wherever a camera needs to go, as opposed to running Cat5 AND power.)
I found a
24 port "midspan" (the picture shows a 48 port - that would be nice) that injects power the way I want it.
I also found an enterprising IT tech who
made his own multi-port injector from a patch panel.
I really think PoE is the way to go. Of course there's PowerLine, where you transfer data over standard power wire, but I don't know much about that.