"Coffee Shop" use case

[jimpick]

This topic came up this morning during "IPFS Community Office Hours".

It should be possible to add a file to an IPFS node running on your laptop while in a coffee shop (behind a NAT), and have it discoverable on the network.

It should then be possible to close your laptop, go to another location (also behind a NAT), open up the laptop, and still have the added file be accessible.

I think it would be interesting to build some comprehensive manual and/or automated testing around this use case, plus maybe a guide to explain how things are supposed to work with NATs.