I just found a new way to access the Gmail address book data. The trick was shared on a different site and may be a glimpse to an address book API.
Log into Gmail and enter this address:
http://video.google.com/contacts/data/contacts?thumb=true&groups=true&show=ALL&enums=true&psort=Name&max=500&out=js&jsx=trueGoogle video is using contact data from Gmail so you can share the video with your Gmail contacts. The interesting thing is all the contact data is there, not just email addresses.
The page the script is lifted from is here.