USB_ModeSwitch is (surprise!) a mode switching tool for controlling
"flip flop" (multiple device) USB gear.

USB_ModeSwitch makes this process easy to handle by taking the important
parameters from a configuration file and doing all the initialization
and communication stuff, with heavy help from "libusb". It is mainly
used automatically - via udev events and rules - to do the switch
without any user interaction. But it can also be run as a command line
tool, usually when trying to make unknown devices work with it.

WWW: http://www.draisberghof.de/usb_modeswitch/