FidoNet over WiFi nodes that only activate intermittently on a varying schedule would be very hard for the authorities to track down. Just use a strong stream cipher to produce the schedule.

Very cool. I've been thinking about something like this (asynchronous message transfer) lately. I would want to use good public key crypto for message signing and encryption. If it was built as a pass-the-note game (with points, achievements, etc...) that ran on phones and could talk to other phones via bluetooth and wifi, I could see it getting pretty popular in schools. The protocol should also support transfer via thumb drive (dead drop) and internet (if available).

See also: http://en.wikipedia.org/wiki/UUCP

I used to run all of my email via UUCP (over tcp mostly, but when I moved across country twelve or so years ago, I switched to dialup).

You get file distribution, usenet, routing, email and it's not hard to layer other services on top of it.

You can run a mailing list on a loosely connected machine without a TCP/IP stack if you wanted to.

When I was in secondary school, I participated in Fidonet via floppy disk. My friend who had a modem would transfer messages from fidonet to floppy disk and back, and bring it to me each day.

What about a BBS for dial-up?