At Mint, I spent all day (and some of my night) building Islandoo, a social networking site with the current focus of auditioning people for the British reality show Shipwrecked.
Creating and participating in the Islandoo community is a ton of fun, especially once you chat with some new people a bit. But I warn you, it's very addictive.
For some cool Islandoo profiles (IMHO), check out gabsy, sandhi, surferjon, laura1monkey, p_ho, and lynzers. Arrow24 & bockers met on Islandoo and are now dating.
Update 23 Oct 2006: We got a great write-up in Independent and Financial Times (sub. req.). Also, we were reviewed in Mashable and TechCrunch UK a few weeks ago.