While I definitely see the downside of decreased personal interaction, I think the free flowing exchange of ideas is simply fantastic.
I haven't had a chance to explore much, but I've stumbled upon www.ted.com, which describes itself as "a global community of thinkers and doers committed to sharing great ideas." (The acronym stands for Technology, Entertainment, and Design.)
I discovered it thanks to Gmail's news scroll (for lack of a better term), which had a link to this article: Tapping Into TED (I recommend checking it out)
I also watched an 18-minute video presentation by Paola Antonelli, design curator of the MoMA, as she talked about design. It was really interesting.
But alas, I must go back to doing actual work. But methinks I'll be back to this site at some point (when I don't have three papers and a thesis to write).