PHP - Address Book (OpenID)

1. Google:
• http://25labs.com/import-gmail-or-google-contacts-using-google-contacts-data-api-3-0-and-oauth-2-0-in-php/
2. Facebook:
• http://shikii.net/blog/getting-a-list-of-a-facebook-users-friends-with-their-email-addresses/
• http://stackoverflow.com/questions/3611682/facebook-graph-api-how-to-get-users-email
• http://stackoverflow.com/questions/3889463/facebook-graph-api-and-friends-email
• http://www.labnol.org/internet/export-email-addresses-from-facebook/12970/
• http://thinkdiff.net/facebook/php-sdk-3-0-graph-api-base-facebook-connect-tutorial/
• http://giaiphapseo.com/thu-thuat-facebook.html
• http://net.tutsplus.com/tutorials/php/wrangling-with-the-facebook-graph-api/
3. Yahoo:
• http://code.google.com/p/yahoo-api-oauth-flow-demo/source/browse/trunk/?r=2