I'm an Emacs user. How do I learn Vim?

I, too, am an Emacs refugee. By far, the most important step is understanding that, unlike any other editor that you have used before, learning Vi is like learning to speak a language, rather than memorizing keystrokes. I discuss this here:

Jeet Sukumaran: Grokking the Zen of the Vi Wu-Wei

The article that made it "all fall into place" for me is here:
Stackoverflow: What is your most productive shortcut with Vim?
Answer: Your problem with Vim is that you don't grok vi.

Run the command vimtutor, it's like the emacs equivalent you get to from ctrl-H-t.

1. A Vim guide for Emacs users
2. local: What features does emacs have that vim hasn’t?
3. local: Features of emacs that are complementary to vim?