A questioner should have the option to setup a timeframe, which defers the publication of answers given to the question.
I'm very active on Stackoverflow when it comes to
jQuery. Many times if a question comes up, it feels like a race on who is answering a question first. I don't think that this kind of behavior increases the quality of answers (quite the contrary). A lot of people just put in a minium of effort to post "an" answer right away, to then edit it later (several times).
A questioner has a dropdown where he or she can choose between
30 minutes (for instance) before answers are published (30 minutes is probably a little bit too much tho).
Answers which are given during this time period are stored (in the order they were posted), but not released yet.
That should increase the quality for answers like a lot. Everybody has enough time without the haste to be the first one answering.
Again, this should be optional for the questioner. It doesn't make sense to apply that kind of option to a question, which requires a complex answer. But for very short questions, this will increase the quality of answers (my belief). It would outclass on-liner answers at least.