WordPress.com | Social Signal

If you're a WordPress.com user, you've come across Gravatars before. They're the avatar, or user image, associated with your account, and they show up next to your comments - not just on your own blog, but on any WordPress.com blog... and on any other blog or forum that has Gravatars enabled. (The word is short for "globally recognized avatar", and there are plugins available for Drupal, Moveable Type and even the venerable GeekLog.)