Good advice Denby.  Thanks for pointing out where flipping the bird originated.  I can remember working with a lot of young people  when  the " f  "word first became part of everyday language and  being so annoyed at the overuse of it in ordinary conversations.  I felt that there should be a guide or thesaurus  on when and how to use it.  

Must admit that I use the word  occasionally when driving, but that in itself can sometimes be a combat like situation I suppose.