Some sort of rating sytem on answers or feedback about the question asked. Maybe the author if the question and readers can rate the feeback based on its relevance and helpfulness.
I see a huge number of views on questions but very little responses, with a rating system or a simple tumbs up or down icon, reader who may not want to comment can still contribute and add feedback by simple clicking the thumb up or down or assigning the comment a rating. Obviously only available to those who are logged in.
www.azcentral.com has a very quick and easy format on their articles in which readers can quickly thumb up or down without having to write a comment.