Morris also said that if people bring some very dangerous items, they will be fined whether it was an accident or not. "If they bring something like a knife with a blade longer than 3 inches" — Salt Lake International found nearly 4,000 of them in three years — "they could be fined between $100 and $500 whether it is intentional or not."

In a time of so much concern about terrorism — which began when terrorists hijacked planes and crashed them into the World Trade Center and the Pentagon — rates of items surrendered are still increasing.

The number of items reported surrendered grew from 6.2 million in 2003 to 7.1 million in 2004.

The rate of potential weapons found per 1,000 originating passengers also increased from 11 in 2003 to more than 12 last year.

Morris says that is disappointing because TSA has been "preaching the same thing for years" about what can and cannot be taken onboard, but people may not be listening.

At Salt Lake International, placards warn about what is acceptable, as do video messages and even exhibits of banned items. Still, people end up surrendering an average of 164 banned items there each day.

Morris said the most common mistake people make "is they just don't take time to stop and think through what they are carrying" and what is allowed or dangerous.

Harmon said, for example, "Just this past week, someone brought a bottle of tequila that was shaped like a revolver. Someone else brought a 10-pound rock. Someone brought a full can of gasoline for a car that was out of gas at their destination airport."

Morris said, "You would be amazed at how many people just always carry pocketknives with them and don't think about it before trying to go through security."

Of note, when items are confiscated at Salt Lake International, Morris said security officers store them in a locked area and make a daily inventory. Once a week, the General Services Administration collects them. Most are destroyed, but some are recycled, Morris said.

Many such items nationally have found their way to eBay online auctions recently, which has advertised sets of knives, scissors and tools confiscated at airports.

Harmon says the TSA encourages people to check www.tsa.gov for lists of what items are and are not allowed, or to call it toll free at 1-866-289-9673.

Among items that are banned from carry-on luggage are metal scissors with pointed tips, box cutters, knives of any length, baseball bats, bows and arrows, golf clubs, ski poles, ammunition, fireworks, axes, hammers, drills, screwdrivers, mace spray, realistic replicas of weapons, lighters and strike-anywhere matches.