Pat Hawks

When Gravatar has no image on file for a user, this plugin takes over and searches for a Facebook, Twitter, or Gmail profile picture to use in it’s place.

Better Avatars

Replace empty Gravatars with profile images from Facebook, Twitter, or Gmail

Dave Ligthart

Import users from vcard as subscribers. 
Works with populair websites such as linkedin and gmail.
Notable features:
<ol>
<li>Import users from vcards as subscribers to your website.</li>
<li>Import user contact data from populair websites such as linkedin and gmail.</li>
</ol>

WP-vCard

Import users from vcard file format. Works with populair websites such as linkedin and gmail.

Better Avatars vs WP-vCard