Here's a story about plans for a new emergency alert system in the American Jewish community:

It is believed to be the first crisis alert system serving a specific community in the United States.
The project, called Secure Community Alert Network, or SCAN, includes the leading Jewish organizations in the nation, as well as hundreds of Jewish community centers, federations and educational institutions.
...Hoenlein said in an emergency, SCAN will immediately notify about 150 contacts across the country via e-mail, pager, telephone and fax. SCAN will not stop signaling until the message is received. The contacts can then alert their memberships.
“We will activate this in a crisis, as circumstance demands,” Hoenlein said, stressing that the network “will be used on rare occasions” and not for general information.
An advisory team of law enforcement and Jewish officials will determine when SCAN will be activated.
Hoenlein noted that Jewish communities in South Africa, England and Australia have such alert systems, saying “it’s a good question” why American Jewry has lagged behind.

The network is apparently contracting to use certain communications technology that has previously only been used by the government and military.
This looks to be a fascinating experiment in creating small-scale information networks, and I'd expect it to be replicated if it works well. The story doesn't say, but it doesn't seem like the information flows from the bottom up. But a network on this scale should be able to accomodate such information flow.
This network could make the job of government easier in an emergency. Congratulations to the Jewish Week for picking the story up; it should attract more attention.