Want to become invisible? Forget about magic potions or miracle creams. Just pick any street corner in downtown Salt Lake City. Stand there awhile until you see a taxi coming. Then, step forward and yell, "Taxi!"

Poof! Just like that you will vanish, at least in the eyes of the cab driver. That's because, by law, he or she is not supposed to stop to pick you up. Any driver who did so might create a traffic jam among all the horse-drawn carriages trying to move through downtown.At least that's the best guess. Officials in the mayor's office aren't exactly sure, but they believe the city's law against hailing a cab dates to the days when people put oats, rather than gasoline, into the objects that propelled them around town. How it stayed on the books this long is anyone's guess, but it remains one of the oddities of local life.

Actually, it's more than just an oddity. Imagine how out-of-towners feel after several minutes of yelling and whistling at each passing cab. The anti-hailing ordinance is bad for public relations, civic pride, tourism and just about any other aspect of the way outsiders view the city. It is a nightmare for the Convention and Visitor's Bureau, and it would be a disaster if the law remained on the books when the world comes here in 2002.

So it ought to be easy to get rid of, right? Wrong. The city has been working on it for about two years now and had to cancel a public hearing scheduled for this Tuesday so it could work on it some more.

The reason is that taxi regulation is about the most difficult and agonizing process any city can venture into. The anti-hailing ordinance has become tangled with a total overhaul of the city's ground-transportation ordinance, one that would increase insurance requirements and, believe it or not, fines for cab drivers with grooming problems. Anyone found not to be "free from offensive odor," for example, would be fined $175. Imagine if all of us had to submit to such a law. My 3-year-old would be behind bars.

But the real sticking point at the moment has to do with added insurance requirements and with the city's insistence that cabbies not charge people for the time they spend sitting in traffic jams. The latter is particularly troubling for cabbies these days, what with freeway and light-rail construction making travel about as easy as getting a confession out of the president.

The cab industry's contention is that the driver is at work during the time he happens to be sitting at 2100 South and 300 West, waiting for the construction trucks to clear. If not for traffic, the driver could be out hustling more business, making more money. Therefore, the companies want to be able to charge for time as well as mileage.

But city officials believe that would give drivers an incentive to move slowly, to deliberately seek out traffic jams and to take unwitting passengers on a scenic route to their destinations.

Perhaps the strangest part of the proposed ordinance is a section that would allow a person with up to three felony convictions to drive a cab, provided he or she can demonstrate a reformed moral character. No one would tell me where this came from, other than it is apparent someone out there with a prison record wants to drive a cab.

Free-market advocates (and I count myself as one) might question why cities need to regulate the industry in the first place. The answer is twofold.

First, taxi drivers play an important public relations role for the city. Often they are the first and last impression a visitor has of the place, and they are vital to a host of other industries. Second, and most important, taxis don't lend themselves to free-market principles. People don't shop around for the cheapest taxis. They grab whatever is available. If the cab industry was deregulated, companies would operate only during peak hours and in areas of peak demand. Fares would increase and no one would be able to ensure that the vehicles were safe.

So the city needs to regulate its taxis. It needs to limit their numbers and sniff-test their drivers. But it needs to know the task will never truly end, especially in a community where transportation needs continue to grow.

And, above all, it needs to avoid silly rules that make life harder for people who want to get around. The good news about the law against hailing a cab is that lately it has been given the same status as the state's law against polygamy. In other words, no one is enforcing it. Mayor Deedee Corradini temporarily suspended the ban during a convention of outdoor retailers in 1997, and no one has paid much attention to it ever since.

Still, the city ought to get it off the books as soon as possible.