On New Year’s Eve, Dan Whaley, a tech entrepreneur in San Francisco, got into a black Town Car and was driven one mile to a holiday party. The ride cost him $27. At the end of the night out, Whaley took a Town Car home from the party. This time, the exact same ride cost $135. Whaley was using Uber, a service that allows people to order livery cabs through a smartphone application. On New Year’s Eve, Uber, a startup in the city, adopted a feature it called “surge pricing,’’ which increases the price of rides as more people request them. Customers were not happy. Many felt the pricing was exorbitant and they took to Twitter and the Web to complain. Some people said that at certain times in the evening, rides had spiked to as high as seven times the usual price, and they called it highway robbery.