People rarely comment on this blog (or most non-political blogs, I've noticed), so feel free to share your best lemons-to-lemonade story with me in a comment, and I promise I'll post the best couple of them pronto! Only Once: Turning Lemons into Lemonade
Comments are in some sense an artifact of early days, when very few people had blogs. These days, much as Richard mentioned, it is more common to just write up a blog post on your own site in "response" to someone. All my lengthy comments are done in this way, using either trackback or a short comment just pointing to my own response.
We still need better tools to connect -- we need to be able to talk across mailing lists, newsgroups, blogs -- and comments. And we need to be able to easily follow these conversations wherever they appear.
(and hey, check out Only Once's full post, because it's a good read)