i found this feature really amazing ... that's what we need ... another step to the 2.0 ...
i knew itGravatars is from gravatars.com, which is popular these days, used by wordpress, and many others, now including xenforo.
You can get an account easily, upload one or more images, for one or more emails. And you can use them to have a comment on a blog, or your account on xenforo,, when using that email, showing the avatar automatically. Making it more personal, easier and automated. User-friendly.