Back in the 1980's long distance telephone calls were ridiculously expensive. This led more than one young aspiring geek to misuse the phone network when making those oh so important calls to BBS's on the other end of the country. But I remember sometime around 1988 that US Sprint offered a service where you could call a local number using your computer/modem and connect to some sort of network. After authentication, it was possible to route your connection to another city, and finally dial out like you were local in that city. This resulted in the ability to make long distance connections at a fraction of the cost, and I seem to remember the bandwidth wasn't too shabby either. Does anyone remember the name of this service, or any details about it? I was just curious how it worked, what infrastructure it used, how popular it was, etc.