I sold my iphone through Orchard.com and found the experience very, very, easy and quick. Using their App they are able to do a diagnostic on the phone and give you an immediate price quote. The whole process took just over a week and they are in constant communication with you to let you know what they are doing and when you can expect payment. They send you a prepaid shipping box with easy to follow instructions.
A great way to turn your old your iphone into cash!
Highly recommended website!