It’s in Beta but from Linqia promo page (signup for updates):

Searching for the online community or group that is a perfect fit for you?

Let Linqia do the searching for you.

Linqia is the world’s first online community and group aggregator and meta search engine. It has the largest directory of online communities and groups worldwide.

Through the Linqia Community and Group Profile, you can immediately determine if an online community or group is a perfect fit for you.

Linqia easily connects you to any online community or group that feed your passions, share your interests and fit your needs.

Watch out for the coming of Linqia.

Not sure it’s the first – there’s a few around, including a social network wiki that a year or so ago had a lot of contributions. Can’t remember the link right now.

If you can’t wait for Linqia to offer up social search goodness, start working your way through the wikipedia list.

Now what I want is a secure service that lets me keep track of EVERY logon I have in the world and beyond. Every password and profile URL. And the ability to publish the profile page as a list under a “About Me”. David N Wallace and I were talking about this on the weekend but we reckon there is already a service out there- anyone know for sure? And no, I don’t mean OpenSocial.