Tech Crunch has a review of Profile Linker.

They have one partnership sealed already, with Photobucket, and hope to do more. But for sites where they are unable to get a partnership they’ll have to gather information using the user’s credentials. There’s a risk that networks will simply cut them off.
They have portable profiles:
Portable Profiles allow you to take your content with you anywhere on the web. Mobilize your bio, share your photos.

Best of all, you only need to make updates in ONE place and all your portable profiles will be automatically updated all over the web.

one way they do this is...Don't feel like entering ALL your profile content again?Well we can do all the work for you. Just tell us your Facebook login or MySpace URL and we'll get your photo and more . .

All this proves the time is really right for open standards to do this.