Agreeing with Comments

Should comments placed on the Voter Interface each have a button so that you can agree or disagree with them?

Should comments with the most agreement rise to the top of the list and those with the most disagreement fall to the bottom?

Given that the number of comments is likely to be vast, perhaps there should be some way of organising them other than on a first-come/first-served basis. This could be achieved by this votes per comment system.

It may also be worth dissuading new comments that are similar to previous comments. This may be achievable by automatically matching words in one comment with words in the new one and then presenting a list of similar comments to the commentor. They may then prefer to add an "I agree" vote to an existing one, instead of publishing their own.