I belong to a yahoo group called Stashbusters and one of the tools talked about there is the Fab 4. You pick 4 projects (probably at different stages), put all the others away and focus on them. You could also add in a system of say working for 10 hours in total on one project, then moving on to the next one for 10 hours and cycle through the 4 projects this way. When one is completed you add in another one to the system.