I've been busy working on this... babbleknot.
It is now up on Amazon EC2. I still have lots of work to do, but it's fun and keeps me out of bars.
I need an artist / partner. I'm great at the back-end stuff, but lousy at the front-end. (or so I'm told)
The easiest way to explain it is that
1) it crawls message boards
2) draws pretty pictures
3) figures out "who is who", and their relationships
4) is great for looking at porn
5) and is a privacy nightmare if you use it right
I've talked about this here, and here.