First we should realize that users in fact search for questions not answers. This sounds odd at first but when you think it's obvious.
Knowing the above, how about a list of different ways the question might be phrased attached to each question?
Meta Stack Exchange is a question and answer site for meta-discussion of the Stack Exchange family of Q&A websites. It only takes a minute to sign up.Sign up to join this community
One of the best ways to insure people find what they want when they search StackOverflow is to be relentless about closing low-quality and off-topic questions. These questions just add noise to the system, so the less of these that exist, the better searches will work.
If you see a low-quality or off-topic question, and you don't have close votes, flag the question for moderator attention. If you have close votes, by all means use them. If you see a question that is so uninteresting that it will not attract enough views to get the necessary close votes, flag it for moderator attention, and a moderator will close it.
There are already mechanisms in place for that, do we need more?