Are 'high-tech' border fences headed for America's cities?

Those who listened to President Bush's prime-time immigration speech on Monday may have caught his propositions for higher-tech border security.

But what exactly did the chief executive mean when he vowed to launch "a comprehensive program to construct high-tech fences in urban corridors"?

The statement proved puzzling even to the Border Patrol itself, spokeswoman Corina Robison conceded to CNET News.com this week. After a little investigating, she and her colleagues concluded the president was simply calling for "a lot more" of the border-security technology they're already using, which includes motion sensors and infrared cameras.

Right now, the patrol maintains a variety of fences at the nation's southern boundary, ranging from "pedestrian" fences that are slightly more heavy-duty than your average chain link fence to "landing mat" fences composed of metal that could take days to cut through.

Homeland Security Secretary Michael Chertoff hinted at the direction that border security gadgets may be heading during a Tuesday White House appearance. Pledging pursuit of "next-generation technology," he briefly mentioned that the department used its first unmanned aerial vehicle this year, which he said in prepared remarks "accounted for 23 drug seizures, totaling more than four tons of marijuana, and also resulted in the apprehension of 2,300 illegal migrants."

As for new deployments in the nation's "urban corridors," the president was likely referring to the more populated areas along the southern border, Robison said. For instance, 14-mile fence designed to separate the San Diego vicinity from Tijuana, Mexico remains under construction amid some controversy.

So if you were envisioning thick metal barriers around Manhattan, rest assured for now.