I'm going to have to try this one next week when I fly...

Apparently Gerald Buckley was able to successfully scan his boarding pass bar code, which was displayed on his iPhone screen as a PDF image. I have to assume the scanner was most likely an image-scanning type since a laser scanner like you see in many places probably wouldn't "see" the barcode. Although, I have noticed in bright sunlight that the iPhone screen almost looks like the text is printed on the surface right under the glass, almost like it could have a shadow. But regardless, it's pretty cool.

Buckley describes his experience on his blog.