TellMe is a voice portal that is used by AT&T, and E*TRADE that allows you to get information from just about any telephone. You cannot reach it from a payphone (as this would cause their telephone bill to be even higher).
By calling the service at 1-800-555-Tell, you get access to the following services.
TellMe also handles the calls for 1-800-555-1212, AT&T wireless #121 service, and Utah's traffic service, 511.
Their Blackjack game is pretty fun, especially since you can play against Sean Connery! Well, it's either him or "country style", a crude stereotype.
Paticularly interesting is their announcement feature, which allows one to record up to 90 seconds of whatever they want. This information can then be retrieved via their toll-free number by anybody.
References
http://www.tellme.com/
http://www.1-800-555-tell.com/