LinkedIn or LockedIn

Networking sites can help you to connect with old and new friends.
This is nothing new. One of the first big successes (and failures?) of the web was the networking site Sixdegrees. More recently, Google employees created Orkut, which, in a similar way, allows you to officially state your relationships with colleagues and friends. As does Friendster, Tribe, MySpace, Plaxo, eCademy, and a number of other networking sites. Right now it seems like LinkedIn is in the lead.
Sometimes, these sites actually work. I've used some of them to de-activate a few old acquaintances, which was nice. But there's something very annoying about the networking sites: They're all walled gardens!
If there was only one of them, that would be kind of nice. You would know where to find your friends. But there is competition. Competition is nice, but when it comes to networking I don't want competition without interoperability. Some of my friends are only in Orkut. Others are only LinkedIn. Or should I say Locked In? Once you have entered your profile and connections in one of the systems, you get locked in. There's no way of connecting your LinkedIn profile to your friend's Orkut profile. Or to migrate from one system to another. If you are to connect with all people who have a profile in any system, you will need to enter your profile in all of them. This would require a lot of work hardly worthwhile.
To me, the obvious solution is metadata standardization. Networking sites should agree on an interchange format and an API for accessing remotely stored profiles. If they did, you could use the one site whose tools, style and extra features you prefer, and still be able to connect with all of your friends, regardless of their preferences. Just as you can call a person on a different phone network or email somebody who uses other email software. Unfortunately, standardization doesn't come by itself. Especially when its merits aren't obvious to everybody. Instant messaging, I believe, still doesn't have it. Will networking sites get it? There are people who try to make it happen. I whish them all the best!