Cats would be far more remorseful if they only knew how many hours of productivity are lost on funny cat pictures across the world every day. Then again, the same could be said about random YouTube videos, aimless Wikipedia crawling, and the numerous other forms of online procrastination keeping us away from doing boring (or scary), yet essential, work. The trouble is that pulling the plug is often not an option: Many of us need the Internet for work. One interesting solution is censoring your own Internet usage, blocking out distracting websites while still being able to use the Web for work. This is what open-source utility Cold Turkey Free Edition offers, at no cost and with no ads.

Free browser add-ons such as WasteNoTime for Chrome and LeechBlock for Firefox offer easy ways to block distracting websites, but they are also easy to disable. All you need to do is switch to another browser, or start a private browsing session, and you're free to procrastinate again.

Cold Turkey, modeled after Mac utility SelfControl, takes blocking much more seriously. Specify which websites to block, pick a time frame for blocking, and start. When I used ColdTurkey, I also turned off my smartphone and put it in another room (the application won't do this for you, unfortunately).

When Cold Turkey is active, you are truly locked out of those sites: Opening a different browser (or a private session) won't help. Neither will restarting your computer or killing the ColdTurkey process (it doesn't even run in the background, so there's nothing to kill). And if you try to do something clever like tamper with the HOSTS file to disable blocking, ColdTurkey may detect that and lock you out of your distracting websites for a whole week.

Simply put, there is no way to abort blocking once you're midway through, so you need to carefully consider the websites you block and the time frame. I once locked myself out of Gmail so I could focus on writing, but I finished sooner than I thought and was then unable to submit my work until the lock expired. When you try to access a blocked website, the browser simply fails to find it—just as if you were offline.

Another technical limitation is that Cold Turkey does not let you block site paths. For example, there is no way to block just google.com/reader (Google Reader) while leaving google.com accessible. Since Google Reader is a gateway to endless procrastination (at least for me), my solution was to block Google altogether and use alternative search engine DuckDuckGo instead.

The free version of Cold Turkey offers plenty of features, and is easy to use. You can also donate $5 to developer and self-described "student in need" Felix Belzile to get a more powerful version that can block executables, such as games, and supports a time frame of up to 30 days (compared to 7 days for the free version). Combined with screen-recording utility TimeSnapper, these two programs form a powerful duo of productivity-enhancing tools for changing long-time habits and getting work done faster and with less stress.

Editor's Note 5/1/2013: The Download button takes you to the vendor's site, where you can download the latest version of the software. Mr. Belzile, having completed his Bachelor degree in Computer Science, has changed Cold Turkey to a "pay what you like" model, complete with a slider to determine what proportion you'd like to give to charity and what proportion you'd like to give to the developer.