There have been a number of films and television dramas revolving around the idea of the witness, generally with the word in their title - Witness for the Prosecution, Witness (TV series)[?], Silent Witness, Mute Witness[?], and Witness (1985 movie).
A certain number of witnesses are legally required to be present at weddings and certain other official events to sign the paperwork.
wikipedia.org dumped 2003-03-17 with terodump