Pack your bags -- for an emergency.

According to the federal government, all Americans should have "ready kits" (search) or "go bags" containing items such as three days' worth of water, non-perishable food, a flashlight, an AM/FM radio and a first-aid kit in case of a natural or manmade disaster.

But while most people agree that basic survival supplies could come in handy during a blackout or hurricane, many aren't convinced about a ready-kit's usefulness in the face of a terrorist attack.

“This little tote bag -- what type of terrorism is this going to prevent?" said Juval Aviv, author of "The Complete Terrorism Survival Guide." "If there’s a suicide bomb in the subway, there’s nothing in that bag that will help you prevent it or survive. It's like a bandage over a major wound."

The government, however, says the kits, which they've been pushing in a national ad campaign, would be effective in an emergency if used as part of their three-tiered "Ready" program: "make a kit"; "make a plan" for a disaster; "be informed” about possible threats.

“We're encouraging people to be prepared, whether it’s terror or a hurricane,” said Lara Shane, spokesperson for the Department of Homeland Security (search)’s “Ready” program. “A ready kit includes basic supplies set aside to minimize the disruption.”

The kits have been getting a lot of attention lately, presumably because of lessons learned from Hurricane Isabel, the blackout of 2003 and the TV, radio and print ads.

"If you miss the federal ads, hopefully you see the local ads," said Shane. "We’ve received the most donated media of any campaign in the Ad Council’s history."

At the local level, governments are adapting the federal Ready plan for their areas. New York City, for example, has been promoting "go bags" as part of its Ready New York campaign since early July.

“We’ve taken preparedness and made it more apropos to New York City," said Jarrod Bernstein, spokesperson for the New York City Office of Emergency Management (search). "This is a real New York-centric program."

The Big Apple's emergency plan puts a greater focus on high-rise building and subway safety, issues not as paramount in the rest of the country.

But Aviv says the kits are just another distraction from the real threat.

“It’s like the government-initiated color-code program that means nothing," said the security expert. "Ask people what yellow, pink, green means -- nobody knows."

Aviv also pointed out that having a flashlight or a granola bar won't help victims of a chemical or biological attack.

“What the DHS neglected to explain is that in a biological attack, the effect is not immediate. You should get the hell to the hospital, because they are equipped and at least you have a chance," he said. "With a chemical attack, people close to the attack itself, or the bomb itself, will probably die. Those on the periphery are going to get sick from fumes and should go to the hospital."

Aviv also criticized government officials for taking so long to get the message out -- the DHS came out with its ready-kit campaign in February 2003, one month after the Cabinet department was officially formed.

"Shame on them if after two years, this is all they can come up with. It’s not up to citizens to protect and defend themselves -- this is why we pay taxes," he said.

New York City resident and clinical psychology student Evan Schwalbe, 29, said he recently saw a pre-made go bag in a Manhattan "spy store" and was tempted to buy it.

“I think it would be helpful in a terror attack if stores shut down. You can only go three days without water," he said. "And a radio helps. Also, having an emergency kit may help to alleviate anxiety. I’d like to have two, one for the apartment and one for my car."

But Schwalbe said he wouldn't expect the kits to prevent him from harm in the event of, say, a chemical attack. 

“I don’t think they would be lifesaving -- I don’t think they're meant to be."