I couldn't find a female to female usb adapter or cable here in Killeen, so I used a USB 2.0 hub. Connected the Galaxy to one usb port and a usb flash drive to another. Worked like a charm. That hub was powered and I copied a 1.5 Gb file from the flash to my Galaxy. Was very fast.
Then I tried an unpowered 2.0 hub. Was able to move small files around from my pc to my Galaxy with minimal difficulties. Seemed to lose the connection if I didn't use it constantly. Maybe because of no power. I'd just unplug the Galaxy and plug it in again, and ok again. Haven't had the opportunity to try a large file with that hub.
Unpowered 2.0 hub cost about $18. It's pretty small and wouldn't be hard to carry around. Probably less than anything from Samsung. However, this really isn't a solution for adding additional memory. You might be able to connect a larger flash, but it would be pretty clumsy, flopping around, etc. You wouldn't want it connected all the time.