Called simply Identify, Jones's tool is a Firefox plug-in you can evoke from any web page that has links tagged rel="me". Just click the control key and the "i" key to get a pop-up offering information put together from all around the web about the person the page is associated with. It works on Twitter profile pages, LinkedIn pages, blogs with good markup and other profile pages.

The data that gets displayed can be frightening if you've exposed more information about yourself than you'd like on a rel="me" linked page. Or it can be disappointing if you're someone who wants a well developed web presence but haven't linked profile pages up well. Perhaps tools like Identify will prompt some people to change the way they profile themselves.

The tool is clearly very useful as a way to learn more about people whose usernames you come across online. It's not perfect but it's often quite good. The new Yahoo Query Language helps tie together levers and pulleys behind the scenes. It could use a lot of work still and we hope it gets it. Jones says he made the project as a demonstration and that the early work that's been done so far on the Social Graph API is already able to deliver value.

We've been using another interface built by Martin Atkins for some time and this weekend we saw an even more sophisticated option offered to customers of social media ping server service Gnip. That there are a lot of smart people working on this and offering up even early solutions to a hungry group of users underlines further how valuable social graph search is.

Brad Fitzpatrick wrote extensively about the prospects and importance of the social graph in 2007, while the wheels were turning. He's at the same event this weekend (Social Web FOO Camp) where Jones presented his experimental project but says he hasn't seen it yet. He's very excited to learn about a serious user interface for the service, though, and told us that the Social Graph API is about to ramp up its efforts substantially.

Obviously privacy, web user education and proper support for metadata are all discussions that need to go on, but there's already a lot of data available and connected.

You can download Jones's plug-in for Firefox now or grab this related bookmarklet to click on any profile page: social graph explorer

A nice clickable end-user interface is only the beginning of what could be done by this kind of standards-based cross site people-search. Mark up your profile pages well, folks, it's time to use our data smartly!

This post originally ran under the title Identify: Google People With Two Keystrokes and was very well received. See that link for extensive conversation in comments.