Eric Nakagawa was between jobs last January when he came across a funny picture while surfing the Web: a high-strung cat with an open maw making a garbled request for a cheeseburger.

Mr. Nakagawa couldn't really say why he found the picture so funny. He passed the digital photo to a friend, and on a whim they created the Web site "I Can Has Cheezburger," borrowing from the caption. Something about the strange image or syntax struck a chord with readers. "We started getting hits," he said in a phone interview from his home...