An option is to get a NAS drive. Many different brand/options available to choose from... If you've got the $$, you can get several TB worth of space. Another option is to get an AirPort Extreme (or other wireless router) with a USB port... you can simply plug a hub and your existing external drives into the AirPort and have them accessible via the network without a computer being turned on.
2/22/11 at 7:22am