Force Accepted Answers on Questions by Inactive Users
A lot of questions don't have an answer marked as accepted; even though they have at least one correct answer. This might be because the user is new and doesn't fully understand how SO works, or it could just be that the user is lazy.
This is why I believe that it'd be a great idea to implement a feature so users with >x reputation can vote on an answer so it'd get accepted. Perhaps this would only be allowed in questions with 2+ answers and which hasn't had any answers accepted within three monts after the answers being posted.
It could work like the flag system does; multiple flaggers (or perhaps the review system) results in an accepted answer.