Avatar assignment module

Needed: Module that assigns an avatar to a new member at signup if they choose not to upload a profile picture of their own. The new member will also have the option to choose an avatar from an assortment in an assigned directory on my server.

This module should be able to randomly pick an avatar from that directory if the member chooses not to use one from that directory or doesn’t upload their own picture.

IMPORTANT: Once an avatar is selected, either by the new member or this module, that avatar is taken out of the available choices and cannot be used by another member. Same applies to an existing member who wants to change their avatar.  In that case, the "old" avatar would be available for selection again. Basically, only one member at a time can use any given avatar.

The most interesting profile blocks I’ve seen have an assortment of avatars, with actual photos being the best. If multiple users can select the same avatar, then the profile block won’t be any more interesting than the default (and extremely boring) silhouettes.

Thanks for your consideration of this project!