How do you focus your mind on the task at hand?

(Ha! I just saw that my DIL asked this question in 2006!) I have a number of projects to be working on and much going on in my personal life, thoughts of which keep distracting me. And then there is the Internet….Do you have any tips or tricks that clear your mind and allow you to focus? I’m looking more for ways to organize your brain than organize your tasks or time.