My new favorite productivity tool is this site: E.gg Timer – a simple countdown timer. Whenever I am procrastinating, I will use it to get myself to focus by starting it for 5, 10, or more minutes and telling myself: I will focus until the timer goes off. I have found this approach very effective, and this site helps me. It also helps because if I find myself going to my browser to mindlessly go on some time wasting site (hello, Twitter!) I will see this and I will remember to focus.
Fans of the pomodoro technique will see there is a special timer just for it.
As a bonus, you can use it to do a high intensity tabata workout.
Great tool. Highly recommended.