Hello Karl,
I too am interested in PoE for the nanode. I had tinkered with a similar setup as your plan B, however have made little progress as my electrical knowledge is limited and I was too scared of frying things.
If you do end up with working Poe injectors and ejectors please could you share the design. I am sure others would appreciate it too.
-Steve
For the amount of effort can I recommend a POE injector / splitter from linitx.
No connection, just a very happy customer of Linitx.
Cheers
Stuart
just be aware that for that one you'd need to feed power in for the nanode
I tend to use 802.3af ones as thats what my voip phone uses -- I have
a tp-link 8 port switch on desk (which providees 4 PoE ports, 4
normal) and use their splitters to power non-poe compliant 5 / 12v
stuff
http://www.tp-link.com/products/productlist.asp?class=poe
seemed to be the cheapest I could rind