Chapman said the Anne Arundel success story is just one example of how IP technology can provide the "common language" needed to provide communications interoperability across many thousands of jurisdictions in the U.S. for first responders.

Users attending the Computerworld Premier 100 conference last week in Palm Desert, Calif., added several more examples during a panel discussion.

Greg Meffert, chief technology officer and CIO for New Orleans, said that although half the city remains without working land lines more than six months after Katrina, VoIP-enabled networks have been operating since a few days after the storm.

Meffert said some workers at New Orleans City Hall had started using VoIP phones before the deadly storm hit on Aug. 29. The city has since been expanding the technology's use, he said.

Jan Rideout, CIO at Northrop Grumman Ship Systems, which has facilities in the New Orleans area, said that before the storm, the company had a three-year plan to install VoIP and wireless networks. That rollout has since been accelerated to 18 months. "It's a big part of our recovery, and we believe it's the way to go," Rideout said.