Moneytwins = peer to peer currency exchange system
"The first service that allows individuals and small groups of people to exchange their foreign currency notes directly with each other without using the services of a bank."
LINK NOT VALID, IT SEAMS TO NO LONGER EXIST
"How about exchanging some of that spare money from your last vacation?
That's exactly what Moneytwins.com is trying to facilitate. The site wants to pair people up to trade currencies without hefty bank surcharges. You can make an offer, look for open trades and close deals with people all around the world. Well, theoretically at least. Most people are a little wary of money transfers initiated by African dictators by now, which is why Moneytwins is suggesting to trade with folks in your community. They also have some sort of trust score built into the system, which supposedly prevents you from running down to the harbor at night with 10.000 dollars in your pocket. Or so.
This sounds like a great concept. Not just for those funny bills left over from your last vacation, but also for the increasing amount of transnational families and their informal money transfers - a phenomenon that is also known as remittances. It is estimated that immigrants transfer up to 300 billion dollars back to their home countries every year." (http://www.p2p-blog.com/item-112.html)
Commentary by Sam Rose at http://www.communitywiki.org/odd/SocialSynergy/PeertoPeerCurrencyExchange