Firefox with Greasemonkey: If you find yourself killing a wee bit too much time on less than productive websites, NoAddict is a tiny Greasemonkey script to nudge you back to work.
We've shared a variety of ways to help you steer yourself away from time wasting websites including how to configure Leechblock, a powerful Firefox extension for beating back your goofing off. If you don't want to chew up any memory with an extension nor do you want to spend time configuring advanced rules, NoAddict is as basic as it comes. You install the script and then add websites you want to have issue you a warning. I took a note Merlin Mann's playbook and edited the Greasemonkey script to ask the question "Is this really what you want to be doing right now?" The default was a "Don't get addicted to "Twitter"!! Kill the page, Please.", if you'd like to edit it you'll need to open up the Greasemonkey user script manager by right clicking on the icon in the lower right corner of your browser, highlight the NoAddict script, and click Edit in the lower left corner.
NoAddict won't do anything drastic like ban you from a site, close the tab, or announce to the world that you're wasting yet another afternoon at work playing flash games, but it will relentlessly remind you that you're browsing a giant time sink. If you have your own tips or tricks for staving off the temptation of the ever interesting Internet, sound off in the comments below. NoAddict is a free Greasemonkey script and works wherever Firefox does.