On the Internet Archive, a stupendous piece of historical film from 1927, made by AT&T: HOW TO USE THE DIAL PHONE.
(via Memex 1.1)
Update: Michael sez, "As part of a 'Lost and Found Film' course, I recently had to make a film about telephones, and came across the 'How To Use The Dial Phone' film you linked to. What I found more fascinating was 'Dial Comes To Town,' in which a town meeting is held to demonstrate the use of the new dial telephone. An oversized dial, about three feet in diameter, is used during the painfully long instruction."