A processor-implemented method of placing telephone calls includes inputting a toll-free number to initiate a phone call, determining whether the mobile device is within a North American Numbering Plan (NANP) service area, upon determining that the mobile device is within a NANP service area, initiating...http://www.google.com.hk/patents/US6968214?utm_source=gb-gplus-share專利 US6968214 - Phone number replace code system and method
