I've taken some time to improve my blogs' commenting systems to go beyond what your standard, classic, blog comments section does. Firstly, I finally implemented the front-end to a feature I had planned, and integrated into the back end, all along: threaded discussions. You can now reply to a reply.
More importantly, however, I integrated identi.ca and Twitter. I got this idea from Psychedelic Squid, who only supports identi.ca. My blog now automatically announces new posts on identi.ca and twitter, and periodically (half-hourly for now) checks those services for replies to the announcement that can be imported.
As you can see, I've added the appropriate reply buttons to the bottom of the post, so each user can chose completely freely how to interact with my blog. I'm speculating that this will increase the amount of comments very slightly every now and again. Yeah, right.
All this works better with identi.ca than it does with Twitter: with identi.ca, I can import a complete conversation tree, no matter whether the notices are addressed to me or not. The Twitter API, on the other hand, only allows me to read my own replies timeline, so there's a greater chance of missing replies-to-replies.
I haven't yet added the new buttons to the RSS feeds, or to the summary at www.jollybox.de. I'm planning to do that in due course.