Adam Smith, the father of modern economics, sought to demonstrate that markets (and economies) pre-existed the state, and hence should be free of government regulation[citation needed]. He argued (against conventional wisdom) that money was not the creation of governments. Markets emerged, in his view, out of the division of labour, by which individuals began to specialize in specific crafts and hence had to depend on others for subsistence goods. These goods were first exchanged by barter. Specialization depended on trade, but was hindered by the "double coincidence of wants" which barter requires, i.e., for the exchange to occur, each participant must want what the other has. To complete this hypothetical history, craftsmen would stockpile one particular good, be it salt or metal, that they thought no one would refuse. This is the origin of money according to Smith. Money, as a universally desired medium of exchange, allows each half of the transaction to be separated.[3] 

People in nearly 14,000 cities spread over 182 countries are waiting to rent you a room, apartment, or home wherever you’d like. Since 2008, Airbnb has made it easy for you to find a place to stay wherever you may be headed. Just enter the dates you need, see what’s available, and book your stay. The site even has its own payment system, protecting all parties from fraud and illegal activities. While you may at first only be interested in traveling, you can eventually sign up to be a host for other members. There are no fees to join, and Airbnb keeps a small portion of the host’s price of each stay to operate the business.

@matthewc23 - I love being able to barter for things. You mentioned that you don't really have any specialized skills, but you would be surprised. Depending on your profession, think about any special training you have that a normal person wouldn't have. Some people would be willing to trade for that service. Even things you wouldn't normally think of as being services could be useful to someone else.

An online community in which you can either share free stuff or rent items for a fee, NeighborhoodGoods bills itself as a “social inventory,” enabling members to save money and resources by borrowing what they need to use. While joining is free of charge, you can create private sharing groups for your business or neighborhood for a small fee: $36 for six months.
It’s hard to answer that without actually seeing a modern gift economy in action. Luckily, modern gift economies actually do exist. On a small scale, they exist among friends, who might lend each other a vacuum or a cup of flour. There’s even an example of a gift economy on a much larger scale, albeit one that’s not always in operation: The Rainbow Gathering, an annual festival in which about 10,000 people gather for a month in the woods (it rotates among various national forests around the country each year) and agree not to bring any money. Groups of attendees set up “kitchens,” in which they prepare and serve food for thousands of people every day, all for free. Classical economists might guess that people would take advantage of such a system, but, sure enough, everyone is fed, and the people who don’t cook play music, set up trails, teach classes, gather firewood, and perform in plays, among other things.

For one thing, the barter myth “makes it possible to imagine a world that is nothing more than a series of cold-blooded calculations,” writes Graeber in Debt. This view is quite common now, even when behavioral economists have made a convincing case that humans are much more complicated—and less rational—than classical economic models would suggest.
Anthropologists have argued, in contrast, "that when something resembling barter does occur in stateless societies it is almost always between strangers."[6] 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.[7][8] 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.[9] 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.[10]
Could you imagine having to barter for food and medicine for your kids?  This is something that most Americans today can’t even wrap their heads around.  Many will say that “it couldn’t happen here.”   I highlighted some of the pain that Venezuelan’s were going through in this article, “This is Why We Prep! This is Why We Stay Aware!.”  Make sure you watch the embedded video.  That video is heart-wrenching!  If you have kids, it will be enough to get you to rethink your preps!
I wish I came up with this fantastic idea. SharedEarth is a free site that connects landowners with gardeners and farmers in need of space to grow crops (i.e. starting a home vegetable garden). You can find free access to land in exchange for sharing a little bit of produce with the landowner. In a time of a strong and growing local food movement and concerns about food safety, SharedEarth might just be the most important sharing site of all!

If you need more than clothes, like baby bedding, baby furniture, or even sporting goods, you’ll be glad to find Zwaggle. It’s a network of parents who have joined together to share the expense of getting “new to your family” stuff in exchange for used or no-longer-needed items. You receive Zwaggle points for giving away your things, and you can use those points to get the things you want. Membership is free, and the community is powered by a points system rather than cash. The only money you have to spend is on shipping.
You can use bartering to cut costs with your small business or to reduce personal expenses. For example, a handyman can trade services with a hairstylist. Each person is still getting paid for their work, in a sense, and it can lead to referrals to cash-carrying customers without costing a penny. However, the essence of bartering is simply to trade something you have for something you want or need – and you can do this whether you are struggling financially or have a steady income.
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.
To try a time bank, search online for one in your local area using How time banks are managed varies according to the region, so it is important (and often mandatory) to attend an initial meeting that explains the general rules of your local chapter. Once you do this, you’re ready to start trading away. Your services and contacts are identified through the local time bank website.
Many prepper fiction novels eventually get to a point where there is a barter economy or the characters visit a Trading Post.  For instance, a trading post plays a prominent role in Mark Goodwin’s series, Seven Cows, Ugly and Gaunt: A Post-Apocalyptic Saga of America’s Worst Nightmare.  In the novel, the characters use silver to purchase the necessary items to survive and make life easier.  Goodwin’s novel is a post-apocalyptic EMP story.  The poop has really hit the fan in this one!