I've decided the best way to fix my habits is to type really slow, being sure every keystroke is perfect. Unfortunately, I now type at ~8 WPM, so nobody should talk to me on AIM for a bit unless they don't mind waiting a minute for every response.
While that may work, I'm sure there's a better way. In my typing class, we did drills - like, we'd start with A and S, and the instructor would tell us to type random combinations of those letters, and then we'd compare our results to the instructions; once we became consistent, we'd go to a different pair of keys, and after that, combine the four. It's also important to do pair drills from one hand to the other, because that's the most common time to introduce finger dyslexia, and it's best to nip that in the butt early, else you'll be hogging the backspace key. When you get toward the end of the keyboard with that method, you end up being much stronger with the left hand than the right, which actually turns out to be good since the most commonly used keys are on the left hand anyways.
There are two things I would recommend:
First, break off your backspace key -- well, maybe not
break, but at least pry out the button so you can't easily hit it. This will force you to get in the mindset of typing accurately, and not necessarily fast; don't worry, you'll get fast at it with practice. If you make a typo, just press space and keep trying to write the word until you get it right. When you're done with the sentence, you can go back and remove the typos. This is valuable for several reasons: firstly, you see visually
how bad you suck at typing, and also you see
where your problem areas are, so that you can work on them.
Optionally, you can just not use the backspace key, but that is pretty much impossible to will yourself in to doing.
Secondly, if you find yourself looking down at the keys, get a piece of paper, and stick it between the number keys and the f-keys so it drapes over your hand. I did this when I was learning to type, and what I found was that I still needed to look down at the keyboard to visualize where some keys were, even though I wasn't reading the keys. I doubt I'd have been able to break the habit without using the paper.