Huh? A what? Gravatar? You all probably know what an avatar is, a small image appearing beside your name when you do such things as posting in a forum, commenting a blog post et cetera. Some years ago someone had an awesome idea: why not create a service where you upload your favorite avatar once and when you post anywhere on the web, this avatar is used. Usually you had to upload your avatar to every single site you used, which could be quite a hassle, if you were member of several forums or commented to a lot of blog posts.
Back when it was released, only a few sites had Gravatar support, but today most forums and blogs fully support Gravatars. That means that if you use the email adress there that is tied to your Gravatar account, your gravatar is used!
Some time ago, the people from Automattic (those are the nice guys that brought us WordPress.com) bought Gravatar and have even improved the service since then. So why not give it a try?
Here’s a video with a quick overview of Gravatar: