I love the gravatar idea and want to use it in more areas of my site than just comments on new articles or other ventrian modules that have it integrated. For example we use active forums, and it doesn't support it - i would rather use gravatars than avatars in the forum anyways.

Privat Messages already integrates in with active forums by taking the USERID token from AF. Seems like you could do the same thing to come up with a Gravatar URL for dispaly in AF or other places.

Something like: