There are many services online that allow you to do reverse phone lookups and these are usually the same organizations that provide you with your local white pages and yellow pages.
There may be some services on the Internet that claim to offer free reverse cellular phone lookups, the vast majority are not actually free.
Genealogy forums and message boards offer help, discussion and lookups for researchers.
You can hire a genealogy researcher to help you find these records, or you can call the local library to see if they perform volunteer lookups.