internet - Making Friends

Are you already part of those new 'social networks' that seem to be the latest hype on the internet? I'm still trying to convince people that getting a weblog is a good idea, and now whole new ways of making friends and doing business emerge behind my back.
I had set up an account with linkedin.com and today got an invitation to link up with fellow blogger Isaac Mao, who has already 115 people in his network.
He was also invited for the Berkeley panel I might attend, but he is considering skipping for time reasons. In my case ulterior motives to take up the invitation (yes, my girlfriend) disappeared. She will only start working in California in June, if she can decide what job to take. Going to conferences is a bit of an outdated way to make friends. :-) Let's see what the deal will be there, it still looks like a might interesting get together if you happen to be around.
Had a look at my profile in the system: very, very short and already outdated, I should pay be bit of attention to that too. Are you using these systems to get connected. And does it work?