I discovered today, way behind the blogosphere eight-ball, a site that provides online avatars: gravatar.com. A gravatar is a Globally Recognizable avatar, which means an 80x80 image is associated with an email address. The gravatar service will serve images from its database for use on blogs where you post comments or any other location where an avatar-accompanied email address makes the content a little more personal. The service is very simple, to see the image associated with an email address, you add the MD5 hash of that email address (I use this utility) as a querystring parameter named gravatar_id to the url: http://www.gravatar.com/avatar.php.
In addition to the gravatar_id parameter, you can specify the location of a default image to use if the email address is not recognized, a size (in pixels) to which the image should be scaled, and even an MPAA rating (G, PG, M, X) that represents the highest "tolerance" your site allows. Setting the rating to PG, for example, would mean that only G and PG images are shown on your site. This is a very appealing reason to include gravatar support in the comments section of a blog.
The MD5 hash is a great way to avoid having someone scrape the links for email addresses and allows you to share your gravatar image as a url without fear of revealing the original email address. There are far easier ways to farm email addresses from blogs (as many people who have been bot-spammed have discovered) but it is very refreshing to see the folks at gravatar considering this aspect when designing their service.
I registered for a gravatar this morning, but currently receive a stock image when requesting the image back from the service. I'm presuming that there is some kind of delay, possibly incurred while a person approves submitted images. That would certainly give extra strength to the value of the ratings system. This ties in to the only weakness I've found with the service so far. The documentation on the sign-up process and usage of the system is a little sparse for anyone but blog developers and in-depth users, which may lead to confusion for some folks. I couldn't find any documentation indicating that a sign-up process might be delayed for 24 or 48 hours while images are reviewed, although I didn't find any documentation to the contrary either. I've completed the sign-up successfully, tested that other people who have got gravatar working show up when I calculate the MD5 of their email and plug it in, so I'll just have to be patient and check again in the morning to see if my address registration has worked.
Fortunately it looks as though SubText, on which this blog is hosted, is already integrated with gravatar because an image citing a gravatar url is displayed next to each comment entry in the posts. There seems to be another problem regarding the specification of a default image, which I'll work out over the next couple of days, but for now it's a promising new way to add a little personality to any feedback received. It is kind of cool to think that I'm being rewarded for still using the same hotmail account I set up eight years ago too. If any blogs are migrated or upgraded to a gravatar-aware hosting platform, then any comments I've left over the last eight years with that address will magically be accompanied by my new gravatar. Further, because it is a lookup service versus being a static copy, I can update my gravatar to avoid the image being as stale as the picture on my driver's license.
UPDATE: My gravatar image is now working and is now viewable here.