Import Contacts from gmail,yahoo,hotmail

Hi Guys,

I have been thinking about how this contact import is working.I have seen in many sites,they will be having a option to import a contact from gmai,yahoo and hotmail.I start do research about how it works and what is the secret behind it.
The answer is API,google,yahoo,hotmail is providing the API to get a contact from their sites,only thing we need is username/password thats it. The following links will help you to find how it works and how to configure it.

Hotmail import Contacts C#
Yahoo Import Contacts C# Code
Gmail Imort Contacts C# Code