I'd like to present this edit_do.bml diff to the group....
It alters your friends page to show which, amongst those people that list you a friend, you also list as a friend.
An example
John Doe and Fred both list Alister as a friend.
Alister has John Doe listed.
User Name is friend? John Doe John Q. Doe yes Fred Fred Bloggs no
You know that you could add Fred as a mutual friend, and there's no need to compare the is friend/your friend list..
Potential extentions:
Graphics - ticks and crosses for yes/no
Hyperlink to add username to list of friends (or javascript to insert name in 'Add Friends' at bottom of that page)
Downside: I have not got a live-running local test system, just the CVS - so this is untested. The change isn't rocket-science though, just re-ordered the database search (to collect the who-are-your-friends info) and put another column out, based on that.
Update: The diff above has been verified as working OK, and completes the basic functionality. I can get a test server together to add further to it, or leave as it is (working fine) for now. Your comments appreciated.