Always thought this was BS and Wikipedia confirms my assumption:

In 2002, lecturers and students from the University of Plymouth MediaLab Arts course used a £2,000 grant from the Arts Council to study the literary output of real monkeys. They left a computer keyboard in the enclosure of six Celebes crested macaques in Paignton Zoo in Devon, England from May 1 to June 22, with a radio link to broadcast the results on a website. Not only did the monkeys produce nothing but five total pages largely consisting of the letter “S”, the lead male began striking the keyboard with a stone, and other monkeys followed by urinating and defecating on the machine.