Internet Attention Deficit Disorder is the productivity killer affecting most office workers today - the stringent urge to “browse just a little more” in between your daily work tasks; to peek at the Digg homepage, check out the hottest YouTube video of the day, skim through your blog feeds reading what happened in the last hour, to jump eagerly whenever Outlook or Mail.app alert you of new mail and interrupt all activity when you get via IM a link to a funny picture.
I got know about from zen habits, They suggest some procedures to overcome it. Believe me those steps increase your productivity. At least It worked for me 
