I know it's been mentioned before, but the leechblock extension for firefox is pretty good for that kind of thing: https://addons.mozilla.org/en-US/firefox/add

I know it's been mentioned before, but the leechblock extension for firefox is pretty good for that kind of thing: https://addons.mozilla.org/en-US/firefox/addon/4476 https://addons.mozilla.org/en-US/firefox/addon/4476 It lets you specify rules for different groups of sites. I have HN in a group of sites which I can view for 15 minutes every 2 hours. You can add time windows to that, so you can set up things like "15 minutes every 2 hours between 9-5" or "blocked between 9-5, otherwise 15 minutes every 2 hours". If you're like me notice that every now and then you change your settings to give yourself "just another 5 minutes", there's also the option to have leechblock make you type a 64 character randomly generated string before you can use the settings. That's enough to remind me that I was meant to be doing other things. The downside is that every now and then it'll kick in while I'm typing something on a webpage and the comment will be lost (like with v1 of this comment for instance). If there's a way to stop that from happening then it's pretty much ideal for what I want.