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.)

They’re handy, because they mean you don’t have to create a new profile image on every site where you want to leave a comment. But they’re about more than just images. Earlier this year, Gravatar profiles expanded to include a bio, links to your other online presences and contact info – all publicly available.

And if you’re a Gravatar user and you haven’t filled out that info yet, you’ll want to do it right away. Because yesterday, Gravatar rolled out a new feature: Hovercards.

Roll over a user’s Gravatar on any WordPress.com site, and up pops a box – a Hovercard – with all of that user’s profile information. (Twitter recently enabled something similar on their site as well.)

If you’ve only entered the minimum, your user name will be all that appears. But if you’ve filled out your profile, the result is a thing of grace and beauty – a virtual business card that appears whenever anyone mouses over your image. And if that anyone was curious about you because of the brilliance and wit of your comment, well, you’ve just made an even better first impression.

So: WordPress.com and Gravatar users, head over to your profiles and start entering whatever information you’d like to share. The few minutes you spend could well pay off with a valuable new connection.