Dovester, a post at A Preponderence of Evidence demonstrates that the latest thinking in the social software field is not as brand new as you might think:

The oldest club in Europe, an exclusive French society of dove breeders, used social networking tools since the late 17th century to connect its members via a handwritten newsletter, circulating from member to member, and being amended along the way. A special trust metric had been established, which allowed each breeder to rate his peers, a process in which each vote carried weight based on the casters own ratings. In addition to the mailing, which took roughly one year to travel each of the members, shortcut routes were established, usually between counties, through which smaller groups could reach other groups. To create the shortcuts, each breeder was required to name at least two “sponsors” and four breeders he sponsored. Communications between unlinked individuals had to be established by finding a connection via ones own sponsor.

And alternative currencies have a long history too, as noted by Phil Gyford of Pepys’ Diary fame:

There was a dire shortage of coins of small denominations, such as a housewife needed for everyday shopping. This had been an increasing problem since James I’s day. It had reached such proportions that something was about to be done about it when the [English] Civil War broke out. Shopkeepers evolved a pragmatic solution: trade tokens. In the 1660s, there were 3,543 ‘tokeners’ in the City, the suburbs and Westminster.

So 17th Century London was on the LETS bandwagon. See also this fascinating interview with Bernard Lietaer on money, community and social change (another link pinched from Phil).