An Ames window is an optical illusion, and the guy who invented it--Adelbert Ames Jr.--is perhaps better know for inventing the Ames room, which is the kind of forced-perspective illusion Michel Gondry used in parts of Eternal Sunshine of the Spotless Mind.
Boing Boing posted a couple of cool videos about the window and the room today, as well as a relevant Eternal Sunshine clip.
That's Dean Hutton on The Curiosity Show. Man, I used to watch that show when I was a kid. Was cool!
And here's an Ames room:
And here are Jim Carrey and Kate Winslet getting all Amesy in Joel Barish's childhood home:
Aaaand now I want to watch the movie again.