In vi, I use control+w to shift between the sections of a split window. You can imagine the hilarity that used to ensue. But, it's not an issue anymore. I haven't made that mistake in well over a year.
Similarly, in emacs I use ctrl+n to go down. On FF, this will open 5-20 windows, depending on how long I wait. (I have a very fast repeat.) Pentadacty with emacs bindings has helped with, but occasionally I will hit the key to pass all keys to FF, and once again end up with ~20 windows to close.
Me too, ugh. I also can't tell you how many times I've hit M-d thinking I'd delete a word and then keep typing, and end up writing all over the address bar instead.
Switchers to OS X with a german keyboard layout also experience quite a lot of fun. That's because on Windows, you have to type ALT+Q to get the @ in an email adress.
You have to fight your muscle memory not to type CMD+Q in OS X.
