I just got an email (auto mail, no doubt) from Reid Hoffman, LinkedIn’s founder and chairman, thanking me for being an early adopter. According to his mail, I was one of the first 100,000 members of the site, and they recently passed the 100 million member mark.<br />n<br />nThat was a long time ago that I joined that site. And I still use it. It’s really the only “social networking” site that I take seriously. My main uses of it are to stay connected to former co-workers and keep an eye out for what they are up to, where are currently may be. Related and secondarily, I use it as a way to get in touch with those folks without having to keep my address book(s) up to date. If another LinkedIn member and I are connected, I am able to either pull out their listed email address and send mail directly to that person, or use the function within the site to send them mail.<br />n<br />nThat’s always been a difficult problem to solve, keeping people’s contact info up to date. In fact, when I was at AOL years ago, I worked on a project to improve the AOL member’s address book experience. Even there, within their walled garden of membership, it was not an easy problem. Even though a user may have had a ‘central’ address book, it could be updated from various locations and clients, online and offline. And one of the major sources of frustration was the fact that the original, legacy AOL address book had a limit of 5000 entries. And by the time I was having to pay attention to it, the service had millions of users and going above 5K entries in your contact list was not unheard of.<br />n<br />nBut back to the topic of socially networkables. LI is ok, it strives to remain professional. All the others? I don’t really see the point unless I am really willing to give away all my personal information and current goings-on. Just not worth it.