Search ebay for the following to see what I am refering to since its the only non-wholesalers site I can find that sells the product (can you say black market LoL):
"2.5 HARD DRIVE DISK HDD PLAYER SD MMC OTG HOST"
Features I found on wholesalers sites:
OTG FUNCTION
let you transfer data without computer. Just connect the USB port, use one button, can copy the data from your CF/SD/MMC or external USB device(U disc/card reader/mp3 player ) directly
HOST FUNCTION
support to play the multi-media file in external USB device(U disc/card reader/mp3 player )
EDIT FUNCTION
can do the operations as copy, remove, rename, delete, and etc, for the files and folders in the HDD.