I find social networking technology quite exciting. FOAF (Friend of a Friend) is an interesting specification. It is designed to allow computers to understand the relationships between people using RDF/XML.
There’s not much buy-on to this right now because it is squarely in geek territory. I suspect that as soon as Friendster and Orkut figure out how to monetize their networks and publish an API, this might die off. On the other hand, it is conceivable that FOAF becomes the API to expose social networks to outside developers.
Give the Foaf Explorer a whirl.