From a strange site. Try this, Organic Trade: Towards a Global Green Currency?
The idea of LETS [Local Exchange Trading System] is to foster exchange within local communities. Conventional money is issued by an authority in limited supply to assure that it is generally accepted as valuable in itself, no matter who has it. Such money comes and goes, in, out and through communities. LETS money goes round and round, within the community of its users, because it has no value beyond the ongoing exchange relationships that it supports. It stays within the community. One type of money encourages people to act exclusively, the other inclusively.Self-issued currency that is not convertible with (in other words, that excludes) any but your most immediate neighbours encourages you to act inclusively. Currency that lets you interact with anyone anywhere is exclusive.
It just gets worse.
Yup, the man's a professional academic.