A low information diet.
This doesn't mean you'll become ignorant or an ill-informed citizen. You're simply moderating your intake of information to 'need-to-know' only.
Stop watching the news and reading the newspapers - wait! - This won't mean you won't know what's going on, but just glance at headlines as you pass the papers and try asking your co-workers, colleagues, waiters, or whoever, what's big news in the world that day. Let the news junkies sift and distill for you.
EDIT: I originally posted this in the comments, but decided to include it in the main body of the post. This will work for problem websites as well as email: http://macfreedom.com/ Though it says Mac, a Windows version is also available.
Now, it's time to attack your cellphone and your email. Settle down, it will be OK - everyone got along peachily before they came around and I am not advising you cut them out entirely, just moderate them. How?
Go into your email settings and create an autoresponse (sometimes called a vacation response) that tells people the two times of the day that you check your email - and that's all you will do! Do not make one of the times first thing in the morning - give yourself some time to be productive before you check your email. In your auto-response, give the times you check them and explain that you're doing this to increase your efficiency and effectiveness and, if it's truly urgent they can call you at <your phone number here.>
People can get along without you, even if the business setting, and this will dramatically cut down on the amount of time you spend sifting through your inbox and responding.
If they keep dawdling, politely interrupt with, "I really need to run, could you shoot me an email about this?" or something similar.
Enforce these rules (both with yourself and others!) and you just may find that you have a lot more time on your hands for both work and play.