Popular commenting platform Disqus , which recently raised $10 million from North Bridge Venture Partners and Union Square Ventures, is adding support for a feature that's both nifty and familiar: mentions within comments. It may not sound particularly sexy, but it could actually help foster better discussions in comment threads (more on that in a bit). If you've ever mentioned someone on Twitter you'll be right at home with Disqus's implementation. Start typing a comment, then type the '@' symbol whenever you'd like to tag someone — this could be a user who has left another message in the comment thread, or a user who hasn't participated. The convention is very similar to the '@reply' system popularized by Twitter, and a small overlay will pop up with autocompleted names drawn from both Twitter and Disqus. Tagged names appear with a gray box around them in the published comment, which looks nice.