HabboHotel habitues should check out Dubit, a 3D virtual world, where you can chat with other visitors and invite them back to your groovy customisable apartment. Modelled loosely on London, there's an Underground system, shopping malls, a strip joint, a modelling agency, slum areas, something called Drugs Alley, and loads of advertising billboards for trendy clothing companies. There's also a games zone, though I haven't the patience to figure out how it all works. Pretty exhaustive.

The site has been nominated for a Bafta. Doesn't work on a Mac, though.