I should have been clearer in that the steps I listed are a one-time setup to enable LV. But once setup, all you have to do is press the round Set button to turn LV on/off.
As far as AF, it is done by dropping the mirror as described by Evoryware. Of course when the mirror drops, your LCD no longer displays the scene so you can't exactly see what you're focusing on unlike a typical digital camera where the display stays on the whole time. There's a whole lot of mirror clicking on/off and that bothers me. I'm seeing more chances for wear&tear with all the moving parts. But that's just me.
Again, I will disclaim that is from someone with just a few months of 40D use. I love it though!
