How to convert all text to lowercase in Vim

Question

How do you convert all text in Vim to lowercase? Is it even possible?

Answer 1

Many ways to skin a cat... here's the way I just posted about:

:%s/[A-Z]/\L&/g

Likewise for upper case:

:%s/[a-z]/\U&/g

I prefer this way because I am using this construct (:%s/[pattern]/replace/g) all the time so it's more natural.