I'm quite partial to LeechBlock for Firefox, personally. I can set certain times of day when my 'procrastinating' sites are available, give myself 5 minutes per hour to slack off, and (sort-of) prevent myself from disabling it too easily.
That's the problem with reading HN on an iPad - I don't have root, I can't hack /etc at all. Damn you curated computing! Viva Libre!
I applaud your efforts. Truth is you will be back here in less than 48 hours, if it is longer it is because you took breaks from creating your to do list app in lisp. Good night sir!