Don't centralize the security effort. Decentralize it.
America doesn't need huge centralized databases that track each and every citizen. What it needs is decentralized intelligence. And that means extensive training for law-enforcement and government personnel on the ground, across the country. The country needs Customs personnel who know what to look for at the borders, like the officer in Port Angeles, Wash., who noticed a suspicious driver trying to enter the U.S., investigated further, and found a load of bomb components intended for attacks on Millennium celebrations.
America needs flight-training instructors like the one in Minnesota who alerted the FBI to Zacarias Moussaoui's alleged desire to learn to fly a plane but not to land one. The country needs alert passengers on airplanes, like those who noticed and took down shoe-bomber Robert Reid on American Airlines Flight 63 from Paris.

Go with what works. Don't take away privacy and still fail the test of security.