How are social networking sites influencing the society today ?

Lately social networking sites have caught up in a big way. To name a few,Orkut, Facebook,MySpace are the dominant players.The visible effect is that one can be so conveniently connected to friends, acquaints through these sites.People discovered their long lost contacts through these sites. Even new friendships/alliances are forged through these sites. I have acquainted quite a few B-school grads of the schools about which I needed info.People find their potential room mates for universities through these groups.I know couple of friends in my circle who met their partners on these sites:). With growing user base, these sites are used to advertise products and find suitable candidates for a job.

Taking the online social networking further there are niche online networking areas like professional networking, dating sites, various interest groups networking sites. The world is leveraging the power of internet in the best possible way :)

What have been your experiences in this journey of NO online social networking to full throttle online networking?