I have a really weird habitual way of typing where I use several fingers on my left hand but only one or two on the right. This has served me for years and apparently gives me 80+ words per minute, but it does seem an incredibly weird way to type. This is touch typing but not using the "standard" finger arrangement. While it's probably not a great idea to try and fix something that already works, I thought I'd try and relearn to type the proper way (left fingers on asdf and right fingers on jkl;).
I've been trying out Mavis Beacon and it seems alright, it slowly adds more and more letters to your repertoire allowing you to gain the muscle memory or whatever, and then focuses on speed. The "games" seem a little pointless (is this program designed for kids?), but I guess for someone who doesn't know where the keys are it does a good job showing you which fingers to use and where to move them. As I already knew where the keys are most of the program didn't really aid me. Once you know where the keys are you probably just want to practice typing out text and a program like that won't really aid any more than notepad apart from counting your words per minute and giving you something to type. I agree with Typing of the dead being pretty awesome though, and will definitely help with your speed once you've got the finger arrangement down.
Do all you touch typers use the standard finger arrangement or do you just do your own thing? I think I've come to the conclusion I'll just stick with what I know, it seems to work anyway.