YoVille sounds like some kind of Haribo rip-off, or possibly a rather sugary yoghurt. It's actually an online metropolis buried away in the deepest, darkest depths of Facebook.
Users get a customisable avatar and apartment, a limitless supply of water balloons and the trot of the town.
There's no monthly subscription or up-front cost - all you need to join is a Facebook (or failing that MySpace) account. A few bits of avatar gear and apartment furniture cost real-world cash, but you needn't fork out a penny unless you absolutely crave a virtual Tiki bar.
As part of an on-going crusade to sort the best social networking services from the rest, your courageous correspondent spent a whole 12 hours prying into YoVille's secrets.