On a more personal note, I've written about how people have found me online before, and surprised me a bit. I tend not to promote my LiveJournal, so not many know about it (though FaceBook syndication has changed that significantly). I also don't tend to push my twitter (on an aside, a good comparison of Facebook statuses vs. twitter messages by the ever thought provoking danah boyd). I tend to be pretty introverted, and as I wrote way back in 2003, I blog for myself, not as an exhibitionist.
But, modern social network has definitely changed this a bit - the widespread adoption and broadcast nature of sites such as Twitter, Facebook, and myspace means that We Live In Public. The last couple days has made that more and more apparent; I've had people call me, IM me, or talk to me about "Christmas presents" or ask me about my fender-bender, which I had posted as a Facebook status. I love that my friends are now referring to dates as Christmas presents, even though I still have a "what?!?" moment when they mention presents. The same what moment when people respond to a tweet or a Facebook status update, in person, with out giving any context, just jumping right in, e.g. "I totally agree with . . . "
In any case, the overlap between my online persona and real life used to be small, but it's grown by leaps and bounds in the last year or two. New tech always results in people saying that relationships are weakening, whether it be the land-line, the telephone, IM / Skype, social networking, etc. As the last few days have shown for me, this new technology enhances relationships - I've had interactions with friends I probably would not have had were it not for my posts along with the ability to leverage technology to communicate.
That being said, tech is a poor replacement for face-to-face communication - there's a reason I'll go to Lincoln Lounge or to play blackjack (and no, smart-asses, it's not because I'm an alcoholic or I have a gambling addiction ;). While I'm usually physically drained after social outings, and need time to recuperate and recharge, the personal interactions are important.
The other part I like about the social web is how it lets me play the voyeur. The effects of the internet on job hunting are well known (with Bozeman being the crazy extreme for a while). As individuals, people google their dates. I heart Facebook for letting me see facets of their lives that I may not know about otherwise, and to know what my more remote friends are up to.
Overall, the unions and intersections of the social and online worlds has strengthened and deepen most of my relationships - it's just a matter of realizing the synergistic effect the two have on each other . . .