Large Multi-Touch Screen Interfacing

I am looking to interface to a large multi-touch screen with Arduino, the idea is to interpret its touch coordinates and send them to another device. I have noticed that most big touch screen or touch screen kits use USB to send their coordinates, would it be practical to read a USB stream from an Arduino? Or does anyone have a better solution?

You may have to get the mega adk to do that since its a usb controller

The most obvious approach is to have the thing that is controlling the output to the screen also handle the input from the screen. What is driving the screen display?