If a phone number is for a mobile phone then looking up the location doesn't make sense at all: mobile phones are mobile.
I guess you could try and crawl an index of business phone numbers and associate those with the listed address for businesses, but that's a completely different business from running a geocoder.
You could provide a bit of geographical information about the first three digits of a US phone number. I imagine that's not what users are actually looking for though.
If a phone number is for a mobile phone then looking up the location doesn't make sense at all: mobile phones are mobile.
I guess you could try and crawl an index of business phone numbers and associate those with the listed address for businesses, but that's a completely different business from running a geocoder.
You could provide a bit of geographical information about the first three digits of a US phone number. I imagine that's not what users are actually looking for though.