[EvanAnderson]

There were "reverse" directories published by non-telco publishers indexed by telephone number and/or street address. Those were a lot more difficult to get your hands on.

When I was a kid I remember thinking about how cool it would have been to somehow scan the entire telephone book and have that data indexed differently. (I also thought it would make wardialing s ton easier since you could knock out all the known-residential numbers.)

[mbirth]

Oh god, yes, I remember we’ve got D-Info (German/“D”eutsches phone book) which had that feature. And because the phone books were copyrighted by the phone company’s publisher, the creators of that app hired cheap workers to manually read the phone books and type everything into a database. Similar to clean room design in software development.