Upload & Sell: Off
I copy the files to my iPad using the camera connection kit and from there to a Seagate Wireless Plus 1TB drive. The transfer to the Seagate is wireless, i.e. it creates its own wifi network. Works flawlessly and the drive is quite small and light. I take quite a few SD cards and leave the files on them, so I have then have two copies, one on the card and one on the Seagate. I delete the files from the iPad as I go.
The Sanho devices will work, but are relatively expensive. The Seagate drive was about $90, if I remember correctly, and the Sanho 500 GB model is $500.