What's worse attempting to hail a taxi when there are none to be found or calling a taxi service to try to get one in a timely manner? No need to answer that one, since Taxi Magic literally lets you take matters into your own hands. You can book a nearby cab, track its position on a map and pay for the ride with a credit card, all directly within the app.
Download links: Android | iPhone
See also: Zipcar, TaxiMart, Rocket Taxi