In the good old days, cabbies were renowned for their ability to get anyone anywhere faster than any other motor vehicle (and perhaps some small aircraft).
Today, however, every cabbie seems to have a GPS navigation device (often Garmins). Beyond that, many still even ask for directions. Two weeks in a row, Philadelphia cab drivers have been unable to get from the Airport to the suburbs, and even find themselves asking for directors once they get near their destination, unable to trust their Garmins while unable to get to their destination.
A colleague of mine even had a New York cabbie who couldn't get from the east side to La Guardia airport. He turned on his Garmin and subsequently began making following its advice to make seemingly random turns that got him even more lost.
The art and skill of cab drivers used to be instantly knowing the fastest route to your destination and being able to lightning-quick in game changes whenever needed. Today's cabbies seem to be one step up from a guy with a rent-a-car and Garmin.