I found this neat page at the WriteToDone.com web site that explains using the Pomodoro Technique to get your book finished.
The Pomodoro Technique is a productivity method using time increments to get the necessary work done in a set amount of time. This also provides breaks in the activity, believed to improve clarity and productivity.
Pomodoro comes from the Italian word “pomodori’, meaning tomato. Remember those kitchen timers that look like tomatoes? Of course, any timer will do.
The concept is simple; set the timer for 25 minutes and write. In these bursts of creativity and productivity, you get your work done. If you can find the 25 minute block of time, you can do this.