Sometimes I see answers to questions that are exact duplicates. Perhaps we should have a feature where you can merge duplicate answers together. (Two users get credit for one answer)
I am aware that this is almost what an upvote would do for an answer, in the sense that if someone agrees with the answer given an upvote will help affirm the validity of the answer.
This will keep answers clean, and both users who answer can benefit reputation wise.
Note: There would have to be a limit, so that users can't post a duplicate answer just to get in on the reputation benefit.