Yeah, that's why, as I keep mentioning
, I had already figured the project should go more of a diy route for the POE source (i.e. something like this. Now in that link it's using the POE to power the hub, but I was thinking about doing something similar (which is to say, not 100% the same). My idea at this point is to get a single wall wart rated at 12V <1A. My reasoning is that 12V is a common voltage and will still be in the 6-20V DC range after any voltage loss caused by distance, and 1A would be capable of supplying power to 3 r-pis even under full load (Alpha board was reported to use ~180mA idle and ~300mA under high load) with a little wiggle room left over and anything above 1A would allow me to use more than 3 pis.
Anyway, so you take the wall wart, and attach however many wires you want to the + and - sides in Parallel the other side you can either attach by splicing the ethernet cable directly (which I think would look a little ugly) or by attaching it to a coupler of some sort (I was thinking about using those snap in couplers and putting them in a straight line enclosure, that's how I spell classy!
). Then on the other end you reverse the process, if you do it right, then the power wires are physically disconnected before it reaches the router or the r-pi. I've seen some people actually wire the power directly onto the router, but unless I knew for a fact that the router could handle that, I'd want to use one of the methods above for safety. Also, I might even put a little fuse break between the PS and the connectors to protect from over voltage and to protect the PS in case one too many r-pis are placed on the line.
Of course, I realize that all this could be done much more easily by using an injector, but the point of this is DIY! Using a pre-made injector is just plain boring!