Quite often I see general or simple questions attracting many answers in a few minutes time.
Often this is because many people see the question at the same time with no answers, and jump to the rescue. They either don't see the other answers before they submit, or don't want to stop at 90% of the answer. Finish what you started, right?
This is of course very competitive and democratic, but I still think this is a bit of a waste of effort.
What I thought of was this: Suppose that if a new question is posted, it is initially only visible to a randomly selected 10% of SO visitors. This random audience gets a head-start of 5 minutes to type in an answer. The question is visible to the other 90% as soon as the 5 minutes are over, or when the first answer is posted. The other 90% can then see the question, and verify that it makes sense, and post their own view if they don't agree.
The plus is that we will spend less time duplicating each others work. The downside is a delay in answering questions. But I don't think 5 minutes is a big deal. I would expect that the person asking has already spent hours to investigate, and something like 20 minutes to search for duplicates on SO, and typing in a properly phrased, tagged question.
You might also not like the idea that you will see 90% of the questions with a delay, but for all questions combined you have the same odds as everyone else.