Logged in users, post as guests?

[omega]

Q: Is it possible for Logged in users to post also posts as guests?

Reason this would be useful is to allow guest posting, that can only be viewed when logged in.

Currently guest post would be wide to the world.

Sometimes existing users and newbies on certain types of forums would like to be able to revert to guest posting where anonymity is important, "asking for a friend..." type questions!

I also have a vague sense this might have already been covered before but I didn't find the exact thread - Please point me in the right direction id this is duplication! Tx!