When you are browsing through the questions list, in the sidebar to the right there are a couple of text boxes labeled "Favorite Tags" and "Ignored Tags". By adding tags here you can alter the way the questions tagged that way appear.
For instance, lets say that Iron Man 3 just came out, but you haven't seen it yet. If you don't want anything spoiled, you can add the iron-man-3 tag to your ignored tags. Now, any question tagged with Iron Man 3 will be grayed out and hard to see, making it easier to look over them and not accidentally read spoilers.
Also, the favorites tag will highlight questions that are tagged with one of your Favorited tags.