+1 this idea!

[Lebanese Dragon]

The Idea and it's Perks:
I think a cool feature would be able to +1 comments that people make. Instead of necessarily having to quote something and respond, you can just +1 to signal your agreement with the comment. I also would only allow plusing comment just to keep the atmosphere cool and positive. Another reason I like implementing this feature, aside from a convenient way to agree, is a psychological one. Many people who don't feel comfortable posting, or are intimidating by the idea of posting their opinions, aka lurkers, can now have a very subtle way to share their voice. I'd have the +1 be anonymous. Secondarily once they start interacting in this way it will help them to realize it's okay to interact, and may increase the chance that they decide to leave a comment themselves.

Potential Con:
There are dangers that certain people will always get pluses and other people will never get pluses and it'll cause jealousy, and obviously some people will resonate with others more. Another concern is that some people may personally have liked a comment they posted a lot, and may be sad, or have a blow to their ego if it doesn't get a lot of up-votes. Overall though, I suspect everyone will leave comments that get up-voted, and everyone will leave comments that don't. So it should be fairly split up.