This post is being used as a means to demonstrate what a legitimate trackback looks like, and how it should be used. The site it's pinging is Dave Mitchell's "Sparsely, Sage..." blog about West Marin County - a freshly hatched blog that is already building up some impressive traffic stats.
Usually a trackback is a comment that someone is making on something you wrote that is hosted on their site.
Let me explain.
Say you write something about the Bolinas Water Board. Someone from the board reads it and wants to respond. This person also has a blog (or website).
Only their response won't fit into the small space alloted for comments.
So what they do is write a long response with charts, graphs and photos, all in support of your brilliant proposition that the Bolinas Board should just hook up the sewage outflow pipes to the water inflow pipes to create the perfect closed system.
The Board member then publishes this article on their blog and in the little space that says "Trackback" - they put in the web address for your article.
Now the real fun begins. The Board member's site sends a "ping" (like in the old submarine movies) to your site saying in effect "Hey, there's this article here that says that it's related to what you wrote. Here's the first paragraph and a link to the article."
Then, in your comments section, a little comment appears that starts out with the first 200 or so characters of whatever the Board member wrote, usually something like "I was reading Dave Mitchell's brilliant blog the other day, and his innovative (albeit stinky) solution to the Bolinas Water problems sparked a thought ..." (click here for more)
Readers of your blog then can click the link to find out what it is that the Board member has to say. It's a nifty little bit of technology that bloggers use to engage in backscratching, logrolling, one-hand-washing-the-otherism.
One of the things that it does is to help bloggers boost each other's rankings on Google and Technorati. These search engines look to see how important a blogger/website is by checking to see how many people are linking to its content. If you have a lot of original content, a lot of people will link to you, saying "Hey, I read this really original bit of news the other day..."
Thus, Google, Technorati, Blogpulse, et al., all figure that you are someone that is actually putting in work, coming up with interesting, original content, and that as such, you should be rewarded for that.
Now then. (Cue ominous music) The unscrupulous scam artists on the web have figured out that using trackbacks is a really great way to boost themselves up in the Google et al. rankings. Long enough, at least, for them to be able to sell whatever it is that they're selling ("Fix your credit report!" "Get a 500 free porno movies" "Win at online poker!") before people figure out that they're scam artists/thieves/stealing credit card numbers for their white slavery ring in Belarus.
Thus, once a website/blog starts getting to a certain level, the spammers start sending trackback spam. Because if there's a link to a highly-ranked website, it tricks Google et al. into ranking their scam site a bit higher. In effect, the spammers start trading in on your good name and reputation to boost their own criminal enterprise.
The print equivalent would be someone sneaking into your printing press and stuffing a one-page snake-oil ad into the Light before it gets distributed. Actually, that's comment spam - which is somewhat self-explanatory.
I guess trackback spam would be analogous to someone dressing up like a Point Reyes Light paper deliveryman and going around the West Marin neighborhoods and delivering the paper by knocking on the front door and distracting the housewife - whilst a confederate sneaks around the back, jimmys the kitchen door and makes off with Grandma's silver and the Franklin Mint Commemorative Elvis Presley dinnerplate collection.
This is why you get notifications as to when someone posts comments or trackbacks to your site. That way, you can see if it's from a legitimate commenter with something to say - or if it's a guy in a black-and-white striped shirt with a Zorro mask tied around his eyes, wanting to borrow your delivery van for a few hours "to run some errands."
Moving on.
In your case, from what I can see, the comments are not from an outside source or scammer. It appears that for whatever reason, when you posted the new table of contents, with links to all your stories, what that did was trigger the technological "trackback" widget, which took the first few grafs of your post and then put it into your comment section, and sent you the notification to say "Whadday think about this guy, boss? Should we let him take the van? He says his granny is real sick and needs her medicine."
In this case, the guy asking for the van ... is you.