Create an iPad app that can send/receive data via the USB cable?

Question

I want to create an iPad app that connects to another machine, laptop or otherwise, via USB and communicates to some other application I develop running there.

I kno

Answer 1

Not over USB but over RS232 (serial port)

Look here: http://www.redpark.com/c2db9.html

But:

1. The cable uses the old 30 pin connector, but according to them it's compatible with the Lightning adapter
2. The application won't be accepted on the AppStore, it's for internal use only.
3. There is a (small) book that explains how to use this cable to connect an iPhone directly to an Arduino, it's been published in late 2011. "iOS Sensor Apps with Arduino Wiring the iPhone and iPad into the Internet of Things" http://shop.oreilly.com/product/0636920021179.do