Import Yahoo / Hotmail / gmail address book

Hi there,

I have a send this site to a friend button and was wondering if anyone knew of a way to import email addresses, like it does on facebook where you can import your address book from yahoo / hotmail / gmail address books then you just select the appropriate email and the email is sent to them.

I can figure out how to do the send to multiple emails via php but how would I import the address book?

Cheers,

Bob