Haloscan commenting and trackback have been added to this blog.
From Haloscan's FAQ:
Q: What is trackback?
A: Wikipedia defines trackback as follows: Trackback is a system [...] that alerts and allows a blogger to see who has blogged about posts on his or her blog. The system works by sending a 'ping' between the blogs, and therefore providing the alert.
In other words, it creates a web for comments, forming links between related posts on different blog sites ... kewl!