There have been some great projects lately about moving information control into the hands of users such as Move My Data. In that vein there is the idea of profile data using microformats. For example you have a list of your friends marked up on hcard on your blog. When you sign up for a social service then you just input a link to your blog and your friends are imported. And you can have subset’s across services, giving you ease and control.
Decentralization and control by the user is also becoming important in the movement for “Identity 2.0”. If you want a quick introduction then I recommend watching the OSCON keynote by Dick Hardt. There are a few architectures that are being built around this idea but one that seems to be taking off is OpenID. From the official site:
For those used to the normal user/password at every site it can be a bit of a hurdle to understand as it involves external providers and trust (from Wikipedia):
To help understand this here are a few posts you may find useful:
If you’d like to get started learning more about OpenID or implementing it then here are some useful places:
And for those in the library field that may think it’s something to ignore, here’s a nice post about Repositories and OpenID as author identity.