Threaded comments for each page

Right now the "comments" section at the bottom of each page is linear. Once the number of comments gets large, it becomes impossible to navigate. It would be nice to have simple threading to allow easier following of a discussion. The comments should display showing hierarchy, based upon which message was a response to which. Sort of like Slashdot or many others, but without extra fancy stuff like ratings and display thresholds.

This should be fairly straightforward to do, and would make the comments much more usable without needing to resort to a separate forum.