The January 2012 issue of Wired features a short article on well-known books that were written in short amounts of time. Apparently, A Clockwork Orange, On The Road, etc., were churned out in some haste. Assorted book cover designers were asked to redesign the cover for a selected title, and given a three hour time limit to do so.
Here's my contribution for Fahrenheit 451, which was written, on rented UCLA typewriters, in only nine days.
For those keeping track, I spent about two hours (and three dollars) tracking down a used paperback copy of Fahrenheit 451, twenty minutes torching said paperback in my backyard, and about another twenty minutes scanning and cleaning up the results. The soot-covered scanner glass I cleaned on my own time.