If you have a cell phone, check out this link:
Wireless AMBER Alerts Subscribers to this service can enter up to five counties, receive a text message on their phone when an AMBER alert is issued for any of those areas. This service is free of charge, and you won't be charged for any alerts received, provided that your cellular provider is a member.
Excerpt from the site:
"Statistics show the first three hours after abduction are most critical to recovery efforts. Recognizing that wireless technology can help galvanize more than 182 million wireless consumers to assist law enforcement in the search for and return of a child, CTIA- The Wireless Association™, its members and The Wireless Foundation are proud to launch the Wireless AMBER Alerts™ Initiative.
"The wireless industry has officially partnered with the National Center for Missing & Exploited Children (NCMEC) (NCMEC) to distribute AMBER Alerts to wireless consumers who opt in to receive geographically specified messages on their wireless devices through an AMBER Alert wireless messaging system. "