AFTER passing through security at the Minneapolis-St. Paul International Airport recently, Nathan Rau noticed something odd -- stuffed animal puppets, actually -- affixed to two electronic wands used for body scans on passengers chosen for more intensive secondary screening.
''They told me they use the covered wands to screen young children,'' he said. ''They said it makes the child feel a little more relaxed during the process.''
Screeners at Minneapolis are using their heads, Mr. Rau decided.
Mr. Rau, a 31-year-old Minneapolis lawyer, has a fairly straightforward approach to evaluating airport security procedures. ''I'll give praise where it's due, but not where it's not,'' Mr. Rau said.
Praise is due to the screeners in Minnesota, he said. But not for the screeners at Dallas-Fort Worth International Airport, who recently confiscated his car key as a prohibited item.
''I'm leaving Dallas on a Sunday and at security it's the usual stuff -- shoes off, laptop out. My carry-on bag goes through the X-ray machine and I hear the infamous 'bag check!''' Mr. Rau recalled.
Here we go, he thought. ''A screener says, 'Sir, is this your bag?' And I say, 'Yeah, and I need a private room if you're going to go through it,' '' he recalled telling the screener.
Mr. Rau explained: ''As an attorney, I carry documents, and because of the nature of what I do -- I do intellectual property law -- opening them up in a public place could have repercussions for myself or for my clients.''
He was told private rooms were for personal screening, not for screening bags. That was not the case in Minneapolis, on the rare occasions when Mr. Rau said he was randomly selected for a secondary screening. ''In Minneapolis, if you ask, they always give you a private room and they're nice about it,'' he said.
At the Dallas checkpoint, the contents of his bag were dumped on the table. ''They pull out my car key,'' he said.
''What's this?'' an inspector asked.
''My car key,'' Mr. Rau said.
Mr. Rau drives an Audi. Audis now come with stylish ignition keys designed to house the key inside a holder, preventing rips and wear on pocket liners. You push a button on a flat two-inch shaft and the key slides out.
As he demonstrated it, Mr. Rau could see the word forming in the minds of the screeners, now three, on his case: switchblade.
''Now the bells are ringing,'' he said. After running the key through the X-ray machine three times, the security committee reached a conclusion. ''Well, sir, that's a switchblade style, and that's a prohibited item,'' Mr. Rau said he was told. ''We're going to have to confiscate that.''
Paperwork, of course, was required. His driver's license and other identification papers were photocopied.
''And of course, I didn't have my car keys,'' he said. Luckily, he keeps a spare in a little magnetized box under his car. But, it cost $300 to replace the key at the dealer, who must add a computer code for a specific car.
He was carrying his house key at the time. In comparison with the flat Audi key, ''the house key looks like a saw blade,'' said Mr. Rau, who first described the incident anonymously on www.flyertalk.com, a frequent-flier forum.
On its Web site, www.tsa.gov, the Transportation Security Administration has posted a list of items you are not permitted to take on an airplane, in both checked bags and carry-ons. But the list is not ''intended to be all-inclusive and is updated as necessary,'' the T.S.A. says, adding, ''To ensure everybody's security, the screener may determine that an item not on this chart is prohibited.''
Mr. Rau said, ''That is the ultimate out -- it's totally at their discretion.''
Mr. Raus said of his Dallas-Fort Worth experience: ''They were not ultra-rude about it. But you ever get the feeling you're just banging your head against a wall?''
Yes, we get that feeling frequently, his fellow business travelers will agree. Last week, the Business Travel Coalition, in a survey of both individual travelers and corporate travel managers, found that ''inconsistency among airports was the No.1 most troubling aspect of the airport security process.''
That survey, which also elicited opinions about screening in general and about a proposed registered-traveler program that would expedite screening for those who registered personal information and possibly fingerprints in advance, is available at http://btcweb.biz.
Incidentally, it is not clear to me yet whether other Audi drivers have had ignition keys confiscated at other airports. Telephone calls seeking comment from a spokeswoman at Audi of America headquarters in Auburn Hills, Mich., were not returned.