I need that because i'm already using the Agavi framework and things will get messy if i tried integrating Zend too. Is there an equivalent of facebook-php sdk for Google Contacts?
From looking at the protocol on the Google Contacts API i can tell that it's mostly REST and XML based. I don't know Agavi but if it contains some kind of REST client it shouldn't be too hard to implement it yourself.
As for the real answer to your question ... not that I or google know of.