This is the first plugin I’ve ever published. The bulk of the code came from an older plugin that is no longer in circulation. Thanks to Tareq Hasan of Altisona Media who wrote the original.
Why was this plugin revived? It seems reasonable that a member who hasn’t added their own avatar can be represented by mystery man. However, it seems ridiculous that a group without a custom avatar also be represented by the same single mystery man. Find out more about this BudyPress plugin at http://wordpress.org/extend/plugins/buddypress-default-group-avatar/
Next version to include an image as the default group avatar, making it even easier.