Often, as other questions here discuss, you find yourself with one or two answers to your question that is kinda correct. But to be really correct they either need to be rewritten slightly, combined or something else. Or maybe they were not really correct at all, but set you of in the right direction.
I think it would be sweet if I could answer my own question (and mark it as accepted at once) and select other answers that were the helpful ones. My answers could then become the accepted one on the top (with no, or a very small amount of rep) and the ones I marked as helpful could be marked as helpful (with slightly less rep than a regular accepted one) and come right after it.
Rep for upvotes on the accepted answer could give a small amount of rep all the participants.