I've just come across some news about the Baroon Dollar - "a community or complementary currency launching in August 2009, which will be redeemable for goods or services within the Blackall Range and Sunshine Coast Hinterland region of Queensland, Australia."
Although the project is aimed at stimulating business activity within the local area of the Blackall Range and Sunshine Coast Hinterland region of Queensland, there will be printed certificates (the "dollars") that customers and businesses can trade with each other. There is something of a collectible market for curios like this - think of expo dollars and the like. Although they are indeed collected, it's mainly for novelty value.
An interesting aside is whether "hippies" such as the good folks in Maleny (I say hippies in jest and only because some of the folks in that area were described that way by the ABC - and if the ABC said it, it must be true!) are able to bring off a project like this and see it have lasting success. I don't know that someone necessarily needs to have a crewcut to be able to run an economy, and if the website is anything to go by, the hippies of Maleny certainly are a professional bunch!
There are a number of other local communities all over the world that run similar programs, it certainly seems to be more than a flash in the pan. I don't think they'll reach any heady status as collectibles though, although dozens of tiny nations around the world will attest to the steady stream of revenue that selling national currency as collectibles can bring in!
The website statest that "All interest accrued, accumulating, exchanged A$s from currency collectors and tourists keeping their $Bs and conversion fees are used for system administration costs (e.g. production of $B notes, promoting participating businesses), no-interest loans to start up local, small businesses and donations (seed funding) to non-profit, community groups." Anyone need a consultant?