Whenever I browse the QUESTIONS tab in math.stackexchange, I notice that all the questions, even the very basic ones, are already answered. And I also notice that even elementary questions are answered by high-level users.
So I am suggesting that we start a culture where high-level users will only answer the very difficult questions that really require ingenuity or a broad knowledge of advanced math, and leave relatively easy or basic (precalculus, calculus, logic, discrete math, number theory, combinatorics, graph theory, linear algebra, real or complex analysis, recreational math) questions to low-level users, so we can also do our part in our community.
Or maybe this can even be integrated as a feature in StackExchange in which users will be required to input an approximate level of difficulty for their questions (say 1 to 10, 10 being the hardest), and high-level users can only answer questions that are level 6 or above.
Definition: The level of a user is determined by the number of points he has acquired.
[For more info, see comments below.]