Finally there is a real (and official) way that makes your contacts portable: the Google Contact API. Before today all web applications that needed user’s email addresses needed to scrape a user’s email service (like Hotmail, Gmail, etc).

Of course the Plaxo (and our own Skipid) Widget made it easier for developers to create contacts of users.. but all were doing this in an unofficial way. The API creates an official so web applications do not need to ask you for your Google password.. however, Google still allows this old approach (vs. the other approach) .

Dopplr, a travel schedule sharing site, has already implemented it in their beta environment.

Hopefully others will follow so the social web can be totally and officially API based.