ProfileLinker (via TechCrunch) is not just a simple identity service (claimID), but more a place to gather all your web 2.0 profiles into one place, and what do you know your collection of social network profiles is within a social network itself.
This is unlike SuprGlu where you can re-syndicate your web content into one stream, it’s more a Personal Content Network like Ziki and Lijit, you also have a user page within a social network where you can discover other people…I guess it is a meta-social network.
It’s main focus is beyond your personal collection, it’s about being able to discover and communicate with friends by type of network.
Great feat to be able to search over profiles from over 70 services.
What I’m interested in is what Ziki, and Lijit already have…searching full-text across all your social network content, plus Lijit allows you to do this across the content of your contact/friends as well (Ziki has this coming soon, and a search widgit is a must to compete with the Lijit).
These services can also be thought of expert locators as there is an explicit section to tag yourself with interests keywords, plus searching content can display various experts in the top of the results, or if they appear numerous times.
NOTE: Q&A services such as Yedda, also lend themselves to manifest into expert locators.
[ADDED: also see the Internet Address Book]