A travel plan emergency alerting system is adapted to receive, from a user, user information and trip/alert information (including at least an expected time of return from a trip and contact information for an emergency contact person). The system is adapted to determine, based at least in part upon...http://www.google.com.tw/patents/US20040198315?utm_source=gb-gplus-share專利 US20040198315 - Travel plan emergency alerting system
