Uber

https://www.uber.com/

Request a car from any mobile phone—text message, iPhone and Android apps.

The way it works:
1) Request a ride by using SMS or the application.
2) Text an address to UBR-CAB (827-222) or set your pickup location on the map of the application.
3) The nearest driver will be dispatched to pick you up. You'll be notified by text with the estimated arrival time and when the driver has arrived.
4) After the ride, Uber will automatically charge the credit card you have on file. The tip is included. The charge is based on a base fare, and if the driver is traveling under 11mph, then the individual will be charged by time. If the driver is traveling over 11mph, then the individual will be charged by distance.

The great part about this application is that it charges per vehicle, not per person. This app would be more beneficial if there were more than one person requesting a car. It is a sleek black car. This application is mostly based in the San Francisco area currently, but will be expanding in the future. There was talk of it expanding to London for the Olympics.