I'm in the process of moving into a new apartment in downtown Baltimore. As with most photographers, I had some framed prints hanging on my walls. Moving them from one place to another can be easier said than done though. I think I've found a cheap and easy way to do it though. I'm using some three-sided cardboard science fair stand-ups I had been using as cheap reflectors. Just lay the frame face-down on the large center portion of the board, then close the flaps and start taping. The trick is to pinch the top and bottom parts of the board together as you're taping, resulting in a nice, snug fit on all sides. I haven't tried any drop tests yet, but I imagine the board would take the brunt of the damage.
Of course, this will also work for unframed prints that you don't want to roll up.