Hey, I have been looking up web 2.0 applications here:

http://www.go2web20.net/

and found an especially cool one called gravity.

http://www.gravity.com/

you have to request an invitation (which I have) but its a site that has a whole heap of 'worlds' in which you disscuss that topic with other people who are interested in the same thing.

eg. Architecture world (I hope)

Anyway, I've requested an invitation and I'll see what is on there and let you know.

Luv El.