How about connecting via proxy such as the TOR network for one thing?

yea we will just use proxies/tor/encryption etc. and it will all be implemented into the client. Gotta love open source.

You could tunnel the peer-to-peer chat over HTTP port 80
That would be pretty hard to shut down.

I don't think a firewall exists today that could block bitcoin at a national or even isp level, and there wont be one for at least another 5 years a minimum. look how hard it is to block BT, this is similar to that, exept BC uses 80% less bandwidth. as said before, we could use phone modems if needed and it would still work.

I don't think that eme would work well, it would have a lot of latency, and would still be difficult to get a signal from NA to EUR. because the earth is a sphere, it is not visible from everywhere at the same time. im sure at certain times of the day you would take advantage of this, but not all the time. for BC to work well, we need it to be up 24/7 with few times of interruptions, because in just 30 minutes the chain could fork.

Someone could create a wireless connection from Alaska to Russia and act as a bridge. Sarah Palin says she can see the "other side" from her home...

National firewalls aren't likely to have any real effect on Bitcoin, or for that matter, anything else that people would want to block. Encryption at a protocol level solves a hell of a lot of problems, for starters. And face it, if the government actually put up a nationwide firewall that worked by a whitelist (in which event encryption and the like wouldn't help) then we'd have a new government pretty soon in all likelihood... and even if we didn't, there's so many alternate ways available to send data. Shortwave radio signals might even become interesting again!

How about just via email or twitter (splitting the blocks down to fit) or msn or heck like the joke RFC TCP over Social Network using Facebook

I expend some cycles thinking about attacks on the global internet from time to time.  My thoughts always seem to come back to there being a reasonably high likelihood of a successful and lasting attack under two conditions:

 1) Pretty much 100% of governments are on-board and coordinating.  Thus, if it can somehow be the case that some relatively important country or coalition of countries have some interest served by not cooperating, that would be a good thing.

 2) If countries were willing to take very drastic measures to impose their will (i.e., a bullet in the head), _and_ if life was otherwise tolerable without a free internet, I am not sure that there would be a sufficient core of people to keep a mesh network or whatever functional.  I doubt that it will ever be difficult to track down 'terrorist' who are committing the crime of communicating with one another and 'putting the country at risk.'  A country with a developed and technically competent police state infrastructure could likely do so within seconds.  I think that the best counter to this is to work on things now which would make such assertions of 'public risk' appear as clownish and contrived to the general public as they would actually be.