RemarkableHere's this amazing thing Mark Evanier just linked to:
Really, give it a view. It's one of the most rewarding four minutes and change you'll spend on the Internet. Promise.
Then go to Mark's site and check out the video of the dog climbing the screen door. It will make you doubt reality.
While you're there, you might as well read everything else on his site. Trust me, it's worth it.