I'm at my Reed College reunion, reconnecting with old friends. We're all about 35 – 40. I've noticed there's a real difference in my conversations depending on whether we're connected via Facebook and Twitter or not. I post a lot online: folks who follow me already know I live in San Francisco, that I'm a pilot, that I was in Slovakia last year. It's a great place to start.
Before the Internet we had casual social information sharing. Christmas letters, alumni class notes, outright gossip. But online social networks make it way easier and more fulfilling, you can learn as little or as much about someone as you want.
The best thing has been meeting someone I haven't talked to in fifteen years, finding we have a lot in common, then making a point of finding them online while standing there with them. So we can stay in touch. Social media really works to keep a community together.