External hard drives alreadyu plug into USB ports
http://www.bestbuy.com/site/Western+Digital+-+Caviar+Green+2TB+Internal+Serial+ATA+Hard+Drive/9234465.p?id=1218064150518&skuId=9234465&st=western digital&cp=1&lp=5
What will this interface in the middle do besides add a bottleneck to the process?