Well, from an iPod point of view, it would be pretty useless adding just a USB connection, as then all you could do is charge it, but the OP said you could watch video on the seatbacks. The only way you could do that on an iPod is either a 3 pin 3.5mm lead, or the dock connector. the 3.5mm lead doesn't give you power, so I assume they are talking about the dock connector.