Nothing turns a group of levelheaded Americans into a pack of snarling dogs faster than a discussion of media bias. "FOX spews rightwing lies!" barks one side. "The New York Times only cares about the liberal agenda," growls the other. Both sides exaggerate, but examples of media bias -- both liberal and conservative -- do exist. And in a contentious political climate, they're impossible to ignore.

As you may remember, I'm a firm believer in the maxim that you've got to trust somebody in this world. None of us can know firsthand everything that's going on in the world; we all have to rely on other people to tell us what's going on in Iraq, on K Street, or in the White House. But who (or, more correctly, whom) do you trust to give you the truth on politically charged issues? A particular news show or station? A commentator or pundit? A blogger?

Perhaps more importantly, how does a public figure or news organ gain your trust? How can they lose it? And if you only believe some of the people some of the time, how do you pick and choose?