A literal Turing machine

Via Boing Boing: A man named Mike Davey has produced a literal Turing machine using a dry-erase marker, a camera, a logical controller and a massive role of film backing tape. Alan Turing famously created the concept of the Turing Machine, which was a conceptual model consisting of a read/write/erase head and a tape that could be scanned forward or backward according to the values read and the rules of its programming. That very simple model is capable of performing any computer algorithm and is one of the concepts at the heart of computer science, but it was always just a thought experiment. Until now I don't believe a literal Turing Machine had ever been built.