UberCab sounds like a great service (with a cool name): It lets you order, pay and rate cabs through an iPhone application. The driver gets to rate customers, too. Because drivers are also using an iPhone app, Michael Arrington speculates on TechCrunch that this enables virtually everyone with a car to also become a (part-time) cab. UberCab is currently available only in San Francisco, but has plans to expand to other cities.