Distraction-Free Web Browsers
Of course the chief cause of distractions and a decline in general productivity is the Web browser. The moment you open your browser you're just a new tab away from hours of distraction; worse, most of us need to stay connected and have a Web browser open for at least a few sites (email, server management, CMS access etc.) for a large part of the day.
Luckily, you can download Google Chrome and use it to turn any Website you need to use into a distraction-free standalone app, making it easy to keep an eye on the Websites you need for work without letting you get distracted for hours searching random articles on Wikipedia. Google Chrome's Application Shortcut feature creates a Website-specific browser that will open and run only the single site you tell it to; all you need to do to is select Create Application Shortcut from the Google Chrome Tools menu, which appears when you click on the wrench icon in the upper-right corner of your Chrome browser. Next, select where you want Chrome to create the application shortcut and you'll get a standalone app that will run only that one site.
Unfortunately, this feature only works for Chrome users running Windows and Linux on their PC. Mac OS X devotees looking for a site-specific Web browser will need to take a look at Fluid, a free app built for Macs that lets you create dedicated shortcuts for specific Websites. Pay for the full version ($5) and unlock a few more productivity features, including the ability to add Fluid links to your toolbar so you can have a dedicated Wikipedia or GMail application.
It can be galling to admit how much time we waste during the workday, but with these productivity tools at your disposal (and a little bit of willpower) you should easily be able to make any computer-related task the focus of your attention.