not sure what the official name for this particular cognitive bias is (feel free to enlighten me)
I've usually heard it discussed in terms of the Dunning-Kruger effect, although that seems slightly different than the model the SMBC comic describes; subjective certainty isn't quite the same thing as willingness to opine, although they're certainly closely linked.
My own Mount Stupid was highly general and came pretty early; as an older child or a younger teenager I was prone to holding forth on anything I had a model of, even if I'd come up with the model on the spot based on anecdotal evidence. I generally got away with it as long as I was speaking privately with groups that didn't have much collective knowledge; the appearance of certainty can give you a lot of intellectual status.
I don't think it fully went away until I'd lost most of my political partisanship (motivated thinking seems like a great way to stay on Mount Stupid), but the popularization in my mid-teens of modern Internet forums (BBSes and Usenet had been around for a while, but I hadn't discovered them) probably drove the first nails into its coffin. Suddenly intellectual status wasn't defined by being able to say the most reasonable-sounding thing at any given moment; statements were persistent, and could be effectively refuted well after the fact. Basic fact-checking became a necessity, and actual research became a good idea if I was broaching a contentious topic. Eventually it got to be a habit. I'm probably still stuck in a few local maxima on various topics, but even the foothills on the far side of Mount Stupid are a lot less embarrassing than its peak if you spend a lot of time with persistent media.
Rationality techniques are helpful, especially in estimation of confidence, but knowing to use them seems to be more a matter of style than of knowledge; it's all too easy to treat rationality skills as a means to winning arguments. This certainly falls under the umbrella of rationality, and the Sequences discuss it in a number of places (the first one that comes to mind is the arguments-as-soldiers metaphor), but I'm not sure I'd call it a skill as such.
A little knowledge is a dangerous thing, not sure what the official name for this particular cognitive bias is (feel free to enlighten me). Probably most of us can recognize that feeling of enlightenment after learning a bit of something new and exciting, and not realizing yet how far it is from the mastery of the subject. I suspect that learning the LW brand of rationality is one of those. (Incidentally, if the words "LW brand of rationality" irked you, because you think that there is only one true rationality, consider how close you might be to that particular summit of Mt. Stupid.) See also the last bullet point in the linked comic strip.
As an exercise in rationality, I suggest people post personal accounts of successfully traversing Mt.Stupid, or maybe getting stuck there forever, never to be heard from again. Did you find any of the techniques described in the sequences useful to overcome this bias, beyond the obvious of continuing to learn more about the topic in question? Did you manage to avoid turning Mt.Stupid into the Loggerhead range?
My example: I thought I was great at programming fresh out of college, and ready to dispense my newly found wisdom. Boy, oh boy, was I ever wrong. And then it happened again when I learned some more of the subject on the job...