I'd be more impressed with the cat if they were door knobs instead of handles. When a person needs the aid of a service dog, they usually change the door knobs to handles for this very reason.
[video=youtube]http://www.youtube.com/watch?v=wfpL6_0OBuA[/video]
It's pretty sweet up until 3 mins into the video then it kinda loses half it's appeal, though it's still fun.