3. You get great at estimating work in 25-minute chunks. Being able to exert that level of control is cool.
4. It directly taps into several other productivity systems like the X Method.
5. Sometimes when you have just 30 seconds left on your Pomodoro you start blasting away on your keyboard like you're one of those hackers in the movies. It makes you realize how much you can do in 30 seconds.
I've actually started to do 5 minute pomodoros. It's insane, but also a lot of fun. Especially when pair programming it's great because you can start discussing an issue and suddenly you look at your timer and think, "Woah... 30 seconds just went by. Let's just try it one way. We can change it later if we want". I also write down what I've done at the end of the 5 minute pomodoro. If it is "nothing", then it's a good flag to say that I have a problem.