From Time's site - [link|http://www.time.com/time/asia/features/changed_japan/yufu.html|No Yen? No Problem! - Small town bartering]

Recession-ravaged residents of this tiny hot-springs town found a way to improve their standard of living. Stuck with low-paying and seasonal tourism-related jobs, Yufuin's citizens solved a chronic yen-flow problem by boosting the local monetary supply: they print their own currency.
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Every yufu user is required to sign the notes they issue. Ultimately they will be called upon to redeem those notes by performing a service for the bearer. The specter of weeks spent washing other people's clothes after a yufu spending spree at the sake shop effectively limits the money supply. The moral: being your own central bank isn't so much fun when the yufu stops here.