By default, WordPress will display the selected gravatar in the image to the left, if the person leaving a comment doesn’t have a gravatar account. As you can see, I’ve selected the Identicon option – I think the look pretty ;-) I’m not really a fan of the Mystery Man though – I think it’s because I see it everywhere.
Here are 7 plugins that will allow for even more gravatar options. Some are really funny and some are useful if you use services like Twitter.