Web 2.0

What genre/application of Web 2.0 is most appealing or potentially useful to you and why?

I am pretty interested in most of the Web 2.0 applications; although I know this is not helping to narrow anything down.

I think podcasting is really interesting because I feel like it is bringing back the feeling of old fashioned radio.

Professionally, I think that wiki's and microblogging would be interesting to research because it seems as though it would be beneficial in the workplace and in the classroom.

I also think that social and professional networking are interesting because I have joined those communities and the access to so many people is amazing.