Spell checking in VIM

Today I learned that VIM has spell checking if you're using version 7 or newer. I added the following lines to my .vimrc

set spell
set spelllang=en

You can then use the following keys to manipulate spelling:

zG - Add the mispelled word to the global spelling file
zuG - Remove the just added word from the spelling file
z= - View spelling suggestions for the word