How would a community be able to use bitcoins if access to the internet and thus the bitcoin P2P network was either completely unavailable or only sporadically available from a small number of nodes?

Places such as Burning Man, remote villages and countries under civil strife come to mind.

There might have to be a level of trust for 0 confirmation transactions.

For example, would it be possible to create a separate, isolated bitcoin network with no mining and the disconnected network can get a trusted node to dump the latest block chain onto a USB stick every other day, and copy any information back onto the stick as needed (such as transactions).

What are the other ways to work?   Has there been any testing, design or thought put into this type of situation?