How can I tell if a 30-pin USB cable for an iPhone is genuine? I have many of the 30-pin USB cables for the iPhone, and I would like to determine which are authentic Apple and which are not. (Over the three years that I owned an iPhone 4 and my wife an iPhone 4s, I purchased several "knock-offs"). Is there a good way to determine which cables are authentic and which cables are not?
The cable itself will be stamped with the text: "Designed by Apple in California Assembled in China".  The "knock offs" wouldn't be allowed to stamp their cables in this way.Edit: It would be on the cable itself near the end that plugs into the iPhone (30-pin end).Edit: The photo shows the text I refer to.  This is an example of a genuine lightning connector in which they added a serial number for identification and moved the stamp about 8 inches down from the USB end of the cable.