Another micronation, one with some measure of fame, would be the Kingdom of Lovely.
This micronation arose from a six-part BBC documentary hosted by Danny Wallace called "How To Start Your Own Country." At the end of the series, Wallace formed a micronation called the Kingdom Of Lovely in his flat in London. The micronation officially formed January 1, 2005. However, the national holiday Lovely Day is celebrated September 2nd, which perhaps intentionally is the date of Sealand's foundation.
Due to its televised nature, the Kingdom of Lovely quickly became popular and received many citizens over the internet- around 58,165 by December 2007, in fact.
Wallace's loft was not the original location for the nation- he attempted to haggle over an island being sold for £300,000 but only caused the seller to raise the price. He also 'invaded' Eel Pie Island before settling on his flat.
This Constitutional Monarchy, headed by King Wallace I, has its own national anthem which can be heard here (http://www.youtube.com/watch?v=X-CFz9kYBJI). Its motto is Die dulci freure, or 'Have a Nice Day,' and the micronation's main law appears to be being polite to people. It also has an official currency, the Interdependent Occupational Unit (IOU).
Though Wallace attempted to enter a song of his own creation to represent Lovely in the Eurovision contest (entitled "Stop The Mugging And Start The Hugging"), the sympathetic contest scrutineer Svante Stockselius was unfortunately unable to accept his submission.
Sources: Wikipedia, Micronations.wikia.com, List of micronations.com, Microwiki.org