Data Robotics Drobo 4-Bay USB 2.0/FireWire SATA Storage Array DR04DD10 for $319.95 shipped after a $30 rebate.  Here is a screenshot for your reference.  This is a fairly fancy data backup solution for the technically inclined, and yet it is also user-friendly relative to all its features.  More information about this backup device can be found here, along with a review for your reference.  Note that you might also want to check out the Free Eye-Fi Card Deal with this Drobo.  Most places have it for over $360.