This is my very modest proposal to break out of ones political filterbubble: Customized search engines. Google offers this as a service anyway, and nobody keeps you from putting together a custom engine like I did below, that feeds you articles across the political spectrum.
Throw in some of your favorite blogs, and whenever you are interested in something, you get an exciting hodgepodge of opinions instead of your usual stuff. And you get frequent reminders of what people from other political orientations are actually reading right now.
Timor domini principium scientiae