[dave_au]

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

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.

[Estragon]

Yeah, undop is pretty half-assed, compared to leechblock. If you don't want to be looking at a site, why not block it all together? Simply dimming the screen sounds pretty ineffective. If you want to set up some sort of aversion therapy, tell leechblock to use goatse.cx as its block page. :-)

(If you haven't seen goatse.cx, don't.)