>Bruce,
>
>The long distance phone company I once worked at had a table of longitudes/latitudes that was used for calculating the cost of any call. It had info like phone exchange, county, town name, etc and several other fields.
>I would guess that all phone companies have the same problem and use the same (or similar) tables.
>Someone might be able to combine such a table with a Zip codes table to get what was asked for. I would agree that regular updating would be required, though. These days phone exchanges changes almost as fast as Zip codes might.

The USPS has the same kind of thing (though it wasn't on-line way back when I worked there :~)). I guess the problem might be getting your hands on one of these tables, since they're probably proprietary if not confidential...