Getting rid of my TV, unsubscribing from mailing lists and limiting the time I spend on reddit/facebook/hn/etc to 10 minutes a day was one of the best decisions I've made in a while.
For anyone who struggles with limiting the time -- not necessarily for lack of self control, but simply losing track of the time spent, [this plugin for Chrome](https://chrome.google.com/webstore/detail/stayfocusd/laankej...) is a life saver!
I set it for exactly 10 minutes on sites, and once I cross that threshold, it redirects whatever page you're currently browsing to one that simply says "Shouldn't you be working?".
[This xkcd comic](http://xkcd.com/386/) unfortunately describes my personality to a tee. I've spent literally hours in a single day simply arguing with people on reddit over trivial things that don't matter. Having the abrupt redirect to a page that tells me to question how I'm spending my time is just the kick I needed to realize that, yeah, I should be doing something else other than arguing with strangers on the internet.