Well you just need to find a piece of hardware that acts as a USB host. The Raspberry Pi mentioned above would work, but you'd need a keyboard/screen or scripts to do it automatically. With the right hardware (even a rooted Android phone), you would be able to see the USB drive as just more removable storage just like your PC would.
Tutorial:
1) Have hardware that acts as a USB host
2) Work with the files just like you would on your PC
http://youtu.be/D8Im0_KUEf8
See also:
http://travisgoodspeed.blogspot.com/2012/07/emulating-usb-de...
http://travisgoodspeed.blogspot.com/2012/10/emulating-usb-df...
http://goodfet.sourceforge.net/hardware/facedancer21/