Lisa R. gets a no prize with a crown and scepter on for bringing us The Principality of Hutt River, which appears to actually be the oldest "micronation" in Australia. They even have a home page. Mint coins and stuff!
Shoot. If I'd know'd it was that easy I'd've done it years ago!
Hutt River Province, that self-proclaimed micro-nation on a sheep farm in Western Australia, has been minting its own coins since 1976.