For those unfamiliar, let's control-c/control-v some Wikipediary exposition:
The Pomodoro Technique is a time management method developed by Francesco Cirillo in the late 1980s. The technique uses a timer to break down periods of work into 25-minute intervals called 'pomodoros' (from the Italian word for 'tomato') separated by breaks.No doubt, there are any number of Ben Franklin-type people who will be eager to leap forth from the grave and claim that they were doing this exact same thing centuries or millenia earlier; but the point is that none of them came up with a catchy name for it. Speaking of which, that name comes from the kitschy kitchen timer that Signor Cirillo used in college:
It breaks down like so: 25 minutes on, 5 minutes off. The exactness of using a timer turns out to be fairly helpful in stimulating focus and creativity: no matter how much time you have left in the day, it feels really important to be productive while the clock is running. The break is also timed, which prevents you from getting too engrossed in your chosen distraction. (You've got enough time to get a glass of water and check a few blog headlines, but not enough to go on a snacks-and-YouTube binge.)
The physical object shown above can be purchased here, but who wants an actual ticking clock taking up space when there are easily downloadable apps that accomplish the same thing?
OSX: Pomodoro sticks a little ticking clock in your upper-right status bar and uses Growl notifications to tell you when the timer starts and ends. This is what I used, and recommend.
Windows: Keep Focused is much smaller and simpler; it uses a little hovering clock that, annoyingly, doesn't seem to be dock-able. There are probably other programs out there but this is what I was able to find with some quick googling.
iPhone: Pomodoro Timer costs 99 cents but looks snazzy and seems worth checking out.