Can a USB pen/hard drive be used with a Logitech Revue? Can the Logitech Revue play videos and display images from a USB pen/hard drive?

What are the hardware specifications of the Logitech Revue?
Based on this forum post, I would say yes.  It wouldn't make sense for it to support external harddrives without supporting simpler USB keys.

As for specs, Google returns many results.  Endgadget has an overview, with a link to more details.