For those of you who want to give your blogging a little edge, take a giant leap forward then take the trackback plunge.
Really, I am just beginning to digest it myself so I will try to give you a 101.
You visit someones blog (eh hem) and think, "Hey, I like this post" so you comment, which of course is nice and appreciated (As long as it's not spam). But you really want to show some love, you send a trackback.
In a nutshell you create a post on your blog with the trackback URL of the post that you visited (If they have this option usually it will be shown as 'trackback url'), copy this URL and paste it in the body of your post with a message. Publish the post.
Next depending on your blogging platform (Wordpress, Typepad etc) send a trackback.
Make it easy on you, sign up at haloscan.com they make it easy to import the trackback code into your blogger template.
I have tried this a few times and was awed by the fact that trackbacks that I sent had appeared in the Google search engine in 3 minutes!
This probably went way over many of your heads, not to worry.