Using avatars on forums

I spend quite a bit of time (in fact too much) on forums (or should that be fora?). Anyway, I wanted to devise a couple of nice unique avatars for use in mentioned forums. After looking at the way stackoverflow.com produced unique avatars for each user, I was directed to this site, that explains how to generate your avatar. Basically you're going to need the MD5 hash of your email address. To get this on linux, you'd enter something like this on the command line:
echo youremail@yahoo.co.uk | md5sum

This will produce a string of numbers and hexadecimal characters. You can then use on the gravatar site as follows:

http://www.gravatar.com/avatar/99[various]9f4028c2c.jpg?d=monsterid
OR
http://www.gravatar.com/avatar/99[various]9f4028c2c.jpg?d=identicon
OR
http://www.gravatar.com/avatar/99[various]9f4028c2c.jpg?d=wavatar

Cool hey?
My wavatar is up above. Sexy hey???