Apple Lightning USB Cables
One thing that really annoyed us when we bought our iPhone 5 was the ridiculous cost of the USB charging and synchronisation cables from Apple. This was further execerbated by the fact that Apple charge nearly £5 to post these tiny cables!
This led us to look at 3rd party copies of the cables and we eventually bought this one on Amazon for £5.29 delivered:
The USB plug is very similar but has a slightly larger housing.
At the important end the lightning plug is noticably different. It's not a tidy one-piece moulding and you can clearly see a join in the metal work. The ends of the pins are also exposed on the leading edge. It is also a slightly tighter fit than the Apple original.
These cables are sold on being fully functional, so you could argue a case for a refund quite easily. We bought this one for use in the car though and its sole purpose is to charge our iPhone 5. The lack of synchronisation capability is not an issue for us, given the low cost paid for this cable.