What apps or tricks do you guys use to make HN & Twitter seem less like crack cocaine?
http://ycombinator.com/newsnews.html 7 Nov: Anti-procrastination features Like email, social news sites can be dangerously addictive. So the latest version of Hacker News has a feature to let you limit your use of the site. There are three new fields in your profile, noprocrast, maxvisit, and minaway. (You can edit your profile by clicking on your username.) Noprocrast is turned off by default. If you turn it on by setting it to "yes," you'll only be allowed to visit the site for maxvisit minutes at a time, with gaps of minaway minutes in between. The defaults are 20 and 180, which would let you view the site for 20 minutes at a time, and then not allow you back in for 3 hours. You can override noprocrast if you want, in which case your visit clock starts over at zero.
In any case, I don't think HN addiction is harmful, unless one uses it as an excuse to put off his responsibilities.
There's Chrome nanny or Leechblock for Firefox; plugins which take a blacklist and blocks you from visiting those sites for a certain amount of time, or at certain times of day. I used it for a while and it really helps.