[Anonymouse]

One thing: a taxi turns up, but it's not the one you ordered. To me it makes perfect sense just to swap the two fares around on the system; doing that might give a taxi company an edge in terms of a) saving a passenger's time, b) saving on fuel/electricity - after all, the driver's there. Far cheaper, surely, to swap them about?

Same with dropping someone off where you want to be picked up - why can't they just pick you up? In this case, you're there.