meh
I hate to be a naysayer, but a) this already exists (Shiva Plug, anyone?), and b) it doesn't address the more fundamental problem of who controls the network infrastructure (if you're using this for, say, moving data around during such events as happened in Egypt). If the lines get disconnected by your government/provider/mother you won't get far with a wall-plug server.
That's not even mentioning the enormous potential for abuse of a server that you just "plug in and forget about", considering the general public's level of computer knowledge.
I will say, however, that combined with some mesh networking and someone who knows what he/she's doing and this could be quite an interesting idea.
Biting the hand that feeds IT
