Rather than a comments system, I'd prefer something which polls around for copies of the link to see if it turns up on HN or whatever, then includes those. Free

Rather than a comments system, I'd prefer something which polls around for copies of the link to see if it turns up on HN or whatever, then includes those. Free moderation, better validation. Comments can be important if you're trying to build a community or what have you and want people to stay on site longer. But most people use aggregators of one stripe or another, whether RSS or a link site or Facebook.