The Ability to Hide Questions
There are a lot of questions that I am generally not interested in viewing either because I don't know anything about what they're discussing or don't have an interest in it. This gets cluttered after a while when you're searching for questions that are interesting to you and you keep getting the same ones over and over again. I think a useful feature would be something like Facebook's "Hide" functionality where you can just click a box or something and it will effectively hide the question from you. It would be question-centric instead of based on tags, since some questions that have tags you're interested in just aren't interesting to you (me, ha).
What say you?