This is really great.  (french) Arduino Forum user [SoranneFr] amazed us witha wonderful Minitel hack.

from Wikipedia:

The Minitel was a Videotex online service accessible through the telephone lines, and is considered one of the world’s most successful pre-World Wide Web online services. It was launched in France in 1982 by the PTT (Poste, Téléphone et Télécommunications; divided since 1991 between France Télécom and La Poste). From its early days, users could make online purchases, make train reservations, check stock prices, search the telephone directory, and chat in a similar way to that now made possible by the Internet.

[SoranneFr] used MiniOS, an OS for Minitel. Arduino communicate with the Minitel using the plug in the back of the device

check the forum thread for Code and more info.