A cab ride is like a snowflake: No two are ever exactly alike, and if certain conditions aren't met, it can lead to total meltdown. I've been in smelly cabs, music-blaring cabs, heat-cranked-high on a summer's day cabs and burn-rubber cabs. Perhaps most disquieting for me was the cabbie in San Francisco who, after gliding through a stop sign at the top of Nob Hill, answered his ringing cell phone with a cryptic "yes, they're kicking in, and, man, is this some good s*'&t."

But nothing prepared me for the travails of the cabbie who pretends to know where something is, but really has no clue. I heard that in London, all taxicab drivers are required to take a detailed test on the city's streets, neighborhoods and intersections. This is clearly not the case in Boston, where I found myself for the first time this past weekend. During one low point I was shouting into my cell phone and trying to explain my coordinates to a friend as she tried in vain to triangulate my location using her computer and Google maps. At that point, the driver had shut the fare meter off, at least, but he still wouldn't pull over. I thought back to another time when a cab driver, who flat-out told me he had no idea where the address I wanted was, took out his handheld GPS and charted out a direct course in no time.

Which made me wonder… Why don't all cabbies have these? If a working knowledge of the city isn't required, shouldn't a GPS at least be as standard as the bulletproof glass and badge-number display? When I arrive in a new city, I don't know north from south, let alone Fenway Park from Faneuil Hall. If they can make the GPS a standard cab feature in Oman, then surely Boston can't be too far behind. In the meantime, other than stopping at a gas station for directions, what do you do when you get in a cab in a city you've never been to, and it quickly becomes clear the driver is just as lost as you are?