ROBOT.LK

The question is simple, Let's take Facebook example to understand it well. When we first open our account, we have no friends. So facebook allows you to give your gmail, yahoo or even msn userid and pass and search if any of your contacts are listed. Or to invite them.

How this works? can anyone making an app is able to implement this functionality.

Thank you.

All these companies usually provide and API to grab the contact list. See this php code for Gmail. https://robot.lk/viewtopic.php?f=67&t=1432

This is amazing. See you can import contacts from almost any social network or email service using this free php API.

https://robot.lk/viewtopic.php?f=67&p=2016

Or even better, http://sourceforge.net/projects/contactgrabber

Thank you guys.