I want to back up my files at home onto an external hard drive and bring that HDD to work to keep safe, possibly to photo shoots. I have an internal 160GB 3.5" HDD and want to use that. One problem. I don't want to carry arround two cable cords (USB/Firewire and AC adapter). Anyone know of any manufacturers or reputable sources that make an enclosure for a 3.5" hard drive that is powered off of a USB or Firewire cable?