Who are you trying to get in touch with? Use the information you do know to find a person you are looking for. For example, if you know what city they live in you can look in the yellowpages. If you know what high school they went to, or where they grew up, you can contact their high school because schools usually keep records of graduated students' whereabouts. If you know anything about their family then you can try to contact any family members for more information. Good luck!