So I was perusing Joshuaink, John Oxton’s splendidly autumnal blog, and spotted something quite cool in his comments. Some of the commenters had small images next to their names, making the comments easy to scan for your favourite personality.

In itself this is not a new idea – many message boards are littered with such images (known as avatars) and some blog authors have implemented their own system – Malarkey pins badges to groups of commenters and Dave Shea has experimented with colour coding certain names. What’s different with Joshuaink is that John has implemented Gravatars – globally recognized avatars. This means the avatar images are pulled from a central repository and follow the commenter from blog to blog. If a commenter changes their avatar, this change is immediately reflected across those blogs.

Tom Werner, the creator of Gravatars, has put a lot of thought into the system. A commenter is identified by email address, but the system always uses MD5 encryption so email addresses are never exposed. Before being unleashed to the world, uploaded images are manually checked and rated along the lines of US movie ratings (G, PG, R, X) and blog authors can then say which ratings they will accept. Authors can also say what size avatar they wish to show (up to 80×80) and the image will be bicubically resized accordingly. There are plug-ins for all major blogging systems as well as instructions for PHP, Perl, Python, Java and Cold Fusion.

The only thing that concerns me is the scalability (particularly financially). At the time of writing Tom has served over 7 million gravatars (since release in late July) and rates all the uploads himself (he says he can do 30 a minute). Hopefully, as the system grows in popularity it can survive on donations and volunteers. Either way I like it and Gravatars have been enabled here on Clagnut.