Black market techniques can help in this situation.
The trade has to be instantaneous, face to face meet ups are essential.
an android app is created, you start your light Bitcoin client on your phone, or iphone or whatever. you keep the wifi on, the sellers keep their wifi on.
When you are in close proximity to a seller the app will alert you that there is a seller near by with cash in a public place. It will tell you their going rate and they get to see your buying rate.
you go to the seller you work out a deal, you transact the bitcoins live on the spot using matrix barcodes, they get their fee in BTC the client gets their BTC on the spot.
High risk if your worried about someone having network control over the area maybe.
the other choice is highly illegal... probably.
you create a p2p bank. tricky shit for sure. millions of them. How do you do this?
The BTC atms, a similar concept but digital, the legal route is to create a banking entity like a credit union but make it p2p many small entities linked by miners who take care of the transactions, the banking software is distributed opensource to everyone so anyone can become a bank.
The person acting as bank is also the miner who takes care of the matchups between transactions. they get paid in BTC fees for keeping the flow of money going.
Cash is king in this system, to start it off the first solution has to be implemented as large cash reserves will be needed, people come sell their cash for BTC the buyer and seller are known because of the block ledger, that BTC address marks them both. The serial numbers on the bills mark the proof of ownership. to be a p2p bank they will have to scan those bills and have it be read by the program working on top of bitcoin, the money that they have and don't have is marked on it's own block ledger for anyone to see, no one knows who they are but the address says they have accepted this amount of fiat these serial numbers and when someone comes to sell their BTC those same bills are scanned out any discrepancy when matched to the BTC addresses will note a difference so the right amount of serial numbers have to be dolled out.
All transactions are local, but once in BTC they don't have to be, the Cash is local, BTC breaks the barriers.
either that or I guess people will be sending their digital cash to the bahamas where they can distribute that info to p2p nodes!
but yeah, all this is not required, BTC is it's own bank, all you need is to get that rig fired up! start generating your own coins. of course this will require a little mind bending on your behalf... why are people so reactionary instead of logical?
do you really need an exchange to tell you what a BTC is worth or can you deduce the real price by your understanding of Bitcoin? How much would a bitcoin need to be worth to handle the whole world economy? that would be about 42 billions dollars worth of transactions a day, millions of millions of transactions.
we know how many bitcoins are in circulation, we know the purchasing potential needed to sustain a large economy, what if we all did the guess work and made a mathematical formula that would give everyone the real price of Bitcoin? All that would be required is access to the blockchain to verify the data and a solid formula that was available to everyone. no need for an exchange just access to the blockchain to verify the price of Bitcoin.a mathematical understanding of the factors for an effective currency can circumvent all this, so easily. WE must give up the idea of a exchange by market liquidity and buy and sell rates... we must base it on fact hard cold science.
The best algorithm for determining the necessary flow of BTC will stop the spread of Fiat into the system, fiat will be locked out forever from this economy. Check Mate