It seemed logical that you shouldn't be able to move a rope trick, but when we read over the spell description neither my husband nor I spotted such a limitation. It wouldn't be the first time we overlooked something we were specifically looking for, though. We're using 3.0, so perhaps this was a loophole closed in the revision - it won't be the last time that's happened, either.
If it's movable, not only does the DM have several delightful options for surprising the PCs who think they're tucked away safely, but the wizard balloon can still fail on the description of wind walk, which renders the subject misty and, presumably, unable to grasp a rope. Hence replacing the belt of giant strength with the end of the rope, in hope that the rope will then count as clothing and transform with me.
This is easily the munchkiniest idea I've ever had, and if it's ever going to work, this is the campaign it'd work in.
But I'm dragging us way off-topic.