We "hired" a mini-cab because a friend said she's had good service from a particular company, but DO NOT do this. These drivers usually do not know the city like the London cab drivers do. After we had been waiting 45 minutes for the hired cab, a London cabbie pulled over because he'd seen us almost 30 minutes earlier and thought we might be in trouble. We tried twice to contact the mini-cab company while en route to Heathrow but only got a recorded message. There was an e-mail waiting for us upon our return saying their driver had waited for us for forty minutes and they would be charging us. We have contacted our cc company and are disputing the charge.