Rapleaf.com provides an API by which it gives you a bunch of details once supplied with an email ID. This of course includes their awesome reputation scores and the ability to get a bunch of information about people and the social networks they belong to.

This project is an small PHP library to support this API.

To get started download the zip file featured on this page and go through the readme.txt

BTW, I'm also looking for feedback on this. So please email me at cheerfulguy AT gmail or go to the wiki tab and put your feedback / issues / concerns there. Thank you!