We can't be that far away from the time it makes sense to rip out all the IFE. Seat back screens, monitors, cables etc and start handing out ipad type gadgets. Even if they are attached to the seat and come out of the pockets.

You could let users bring there own USB device (or what ever) and/or pre load them.

The problem with IFE is that the hardware becomes obsolete even before it's released.