Dial-A-Joke
Dial-A-Joke (or joke line) refers to a telephone service that users can call to listen to previously recorded jokes. Jokes are recorded on an automatic answering machine. In the past, many jokes were recorded on cassette tape and then played sequentially, each caller hearing the next joke on the tape.  Modern touch tone phones allow callers to select different joke types: knock-knock, joke of the day, professional humor, random, etc. 

Dial-A-Joke operators will sometimes actually answer the phone, which is called taking a live call.
The co-founder of Apple, Steve Wozniak actually met his first wife by taking a live call on his Dial-A-Joke service.  He started the service as a hobby in 1973, at which time it was the first Dial-A-Joke in the San Francisco Bay Area. Wozniak's Dial-a-Joke line received 2,000 calls a day during its three years of service.

The Original Dial-A-Joke by  Mark Robbins, Ira Goldstein, Ben Weinberg and Jan Lucas
881-2345 Telephone Entertainment Line was created in 1971.

The Dial-A-Joke answering machine was located in the apartment of Mark Robbins and Ira Goldstein on Yarmouth Street in Encino, California. Jan Lucas was the voice of Dial-A-Joke. Mark Robbins built and maintained the Dial-A-Joke answering machine. Ira Goldstein and Ben Weinberg were responsible for content and production of the Dial-A-Joke tapes.

The four got a rubber stamp made that said “Dial-A-Joke ###-####” and stamped hundreds of business card sized pieces of paper and then passed them out in local malls.

Originally, they used a Codeaphone answering machine, but due to high call volume the machine failed.  Mark Robbins designed a new machine centered around a Craig 8-track tape player. About 30 different jokes were recorded on a tape loop. There were two tracks recorded on the tape. The first track had the joke on it. The second track had a beep tone after each joke which turned off the machine. They also had a counter that tracked the total number of jokes given. When they retired the machine, it had over a million calls logged.

Dial-A-Joke run by Mount Hood Chemicals
Located in Portland, Oregon: The makers of C-20 type laundry soap.
Running through the late 70's.  A new recording every weekday.

Dial-A-Joke developed by New York Telephone
In 1973, Y&R Advertising on behalf of the New York Telephone Company booked a recording session in New York City's GT Harris Recording Studios on 55th Street and Broadway with stand-up comedian, Henny Youngman. The project was initiated by NY Telephone VP Executive Glenn Appleyard to become New York City's ambitious Dial-A-Joke variant. The Engineer on the project was Floyd O'Neil, who remained with the project until divestiture of the baby bells. The original recordings, which later included such notables as Jay Leno and David Letterman, were donated to the Smithsonian Institution in the late 1980s.

New York Telephone Company's Voice Automatic Answering System was built by a Georgia company called Audichron. It was first put into service to provide automatic updating of Time and Weather for the New York Metropolitan Area and later adapted for this entertainment function. The system allowed for continuous playback of a complete one-minute message. It was called a "barge-in" system in that an incoming caller could connect to the playing message at any point, hear it to the conclusion, and then the message would play one more time until it was played from beginning to end. The unique part of the system is that it was engineered to allow for thousands of simultaneous connections.

Dial-A-Joke run by James Wayman
Located in DesMoines Iowa, then Crescent City California.

Dial-A-Joke run by Cassie Phoenix
-Located in Catskill, NY and Fairfax, VA.