Anthropologists have argued, in contrast, "that when something resembling barter does occur in stateless societies it is almost always between strangers." Barter occurred between strangers, not fellow villagers, and hence cannot be used to naturalistically explain the origin of money without the state. Since most people engaged in trade knew each other, exchange was fostered through the extension of credit. Marcel Mauss, author of 'The Gift', argued that the first economic contracts were to not act in one's economic self-interest, and that before money, exchange was fostered through the processes of reciprocity and redistribution, not barter. Everyday exchange relations in such societies are characterized by generalized reciprocity, or a non-calculative familial "communism" where each takes according to their needs, and gives as they have.
Make the deal. After you've found a barter partner, get the agreement in writing. Make sure you detail what services or goods will be involved, the date of the exchange (or work to be done) and any recourse if either party reneges on their part of the deal. If you are working through a membership-based bartering association, they will likely provide all the structure and paperwork you need for the deal.
For $75 per year, Capital Bike Share gives members access to inexpensive bike rentals around the Washington, D.C. area. Bike stations filled with 1,100 bikes are located all over the district and nearby towns, and a single membership key grants you access to use and return any of them wherever you are. The first 30 minutes are free, and each additional half hour costs a few bucks. Members can also use the SpotCycle app for the iPhone, Blackberry, and Android device to locate the closest available bike. You can also try a limited plan, like a 30-day pass for $25.