The United States Department of Homeland Security recently released a preparedness kit in case of biological or chemical attack on US soil (http://www.ready.gov). The kit describes the standard survival fare, enough food and water for three days, radio, flashlight, spare batteries...

The questionable items are painter's dropsheets and a roll of duct tape to seal oneself in a safe room.

There was a lot of criticism on that piece of advice, too numerous to list here (ask Google), but one meme that caught on quick was Duct and cover, a pun of another futile civil defense measure from the Fifties: Duck and Cover!

Tlachtga writes: "My favorite part about duct tape was the manufacturers pointing out that duct tape is gas permeable, and thus useless."