Cool tool for blog comments: Gravatar (just acquired by Automattic)

Automattic (the folks behind WordPress) just acquired Gravatar, ("Globally Recognized Avatars"). (Hat tip: GigaOM.) What is it?

an 80x80 pixel avatar image that follows you from weblog to weblog appearing beside your name when you comment on gravatar enabled sites. Avatars help identify your posts on web forums, so why not on weblogs?

How does it work? Behind the scenes, the blogging software sends an encoded version of the commenter's email address; Gravatar returns an image. Plugins or HOW TO notes exist for WordPress, MovableType, Blogger, LiveJournal and several other blogging services and Web development languages. We also found a Python implementation that's not listed on the Gravatar site. (We don't yet support Gravatar here at Blogcosm, though it's been on TO DO list since before we launched the site!)

A blogger has several options when adding gravatars:

• maximum "rating" (G, PG, R, X) to help ensure that the returned icon is appropriate for the blog's audience (though relying on the commenter's own rating)
• icon size, currently from 1 to 80 pixels (Automattic announced future support for 128px)
• fallback URL to display an alternate image if no gravatar is available for the commenter's email address

One potential drawback: fetching an icon across the network for every comment may increase page load times. WordPress users can try the Gravatars2 Plugin from ZenPax. Scott Yang offers a Generic Gravatar Cache based on PHP. Jon Galloway provides details on caching in ASP.NET.

On the business side: financial terms were not disclosed. Gravatar developer Tom Werner is a Ruby fan (blog name: Ruby is Awesome) but Automattic plans to rewrite "to fit directly into our WordPress.com grid" (presumably in PHP). In any case, Tom lists his employer as Powerset (a hot startup which he apparently joined in February) so I doubt that employment was ever in the cards. In any case, congrats to Tom on what I hope was a nice ROI for a very useful service.