Garfield Minus Garfield is a website created and maintained by Dan Walsh. The idea is simple enough - Walsh takes Jim Davis' famous Garfield comic strip, and removes all images and dialogue of Garfield himself. What's left is the darkly humorous and often absurd schizophrenic existential crises of Jon Arbuckle. It's simple, high-interpretation, low-intelligence contextualization based humor, but I find much of it to be sickly hilarious.
See for yourself.
Also, there is apparently a book, a twitter feed, and a short column of Jim Davis himself discussing Garfield Minus Garfield. All of these links are available on the website.