Taxi Magic is more than just some simple phone book app that gives you access to local taxi listings. It will actually dispatch a taxi for you in 25 cities (my own town of Seattle is on the list). It only takes a few moments to step through the taxi request form; your iPhone already knows where you are (or you can enter a different address). And Taxi Magic eliminates the worst part of waiting for a taxi -- the not knowing when it'll arrive, or if it'll ever show up at all. The program's live updates keep you informed about exactly how far away your taxi is and when you should expect to be picked up.
Best of all, Taxi Magic is free and there's no surcharge added to your ride for using the program. Don't forget, though, that if you don't own an iPhone or an iPod Touch, you can still use #TAXI on your cell phone.