Redmine

I suggest to display Gravatar's ident icons instaed of the default icon when a user has no picture uploaded. Each user gets his very own unique icon automatically calculated by his email adress! This can be done very simple by adding a single parameter to the gravatar url!

Please read here: http://blog.gravatar.com/2008/04/22/identicons-monsterids-and-wavatars-oh-my/