London black cab races sat-nav

Sat-navs are all the rage these days, but how would one fare against a seasoned black cab driver with the Knowledge? We decided to take this challenge to one of London's most experience cabbies, Steve McNamara, and capture it on video. With our trusty TomTom Go 520 sat-nav -- not to mention our elite driving skills -- leading us around the highly congested, winding streets of the Big Smoke, we hoped our machine would overcome Steve's years of experience. Find out who crossed the finish line first.