Mike Martel

This plugin adds hovercards (like on WordPress,com (Gravatar), Twitter, Facebook, Google+, etc.) to BuddyPress. Whenever a user hovers over a user avatar, the hovercard shows up.
Hovercards are completely themable by adding a <code>hovercard.php</code> template to your (child) theme.
Based on imath’s blogpost <a href="http://imath.owni.fr/2010/11/23/buddypress-xprofile-hovercard/" rel="nofollow ugc">on BuddyPress xprofile hovercards</a> and uses the jQuery <a href="http://onehackoranother.com/projects/jquery/tipsy/" rel="nofollow ugc">Tipsy</a> library and <a href="https://github.com/rrrene/tipsy.hovercard" rel="nofollow ugc">Rrrene’s hovercards</a>.

BuddyPress Hovercards

Add themable hovercards to your BuddyPress installation.

moallemi

This plugin brings Hovercard popups for your commenters and adds some cool fetures using gravatar.

Extended Gravatar

This plugin brings Hovercard popups for your commenters via Gravatar

BuddyPress Hovercards vs Extended Gravatar