The exchange of one man's (or woman's) work for another man's work  (e.g., plumbing work for chickens & eggs) does the following:

1.  Strengthens ties between man and man, family and family, and community

2.  Allows a family to conserve whatever monetary capital it has

3.  Avoids the need to go to the givers of credit to pay for a service

Sites:   http://seattle.craigslist.org/search/bar?query=barter&sort=rel

            http://www.u-exchange.com/memberlist/United%20States/Washington