Move the population of the hash/username map to a crontab
Use Confluence as an avatar server
When you can't or don't want to reach the internet for avatars or just wish to keep a unified identity across your tools.
Use it in Fisheye
Fisheye allows you to configure the gravatar server URL which you can replace with the URL for your confluence server.
Use it in Bitbucket Server
Bitbucket Server allows you to configure your avatar server through it's properties
Updated to work in 7.0.1+
Privacy and security
Avatar URL configuration is now in Bamboo