Yes, this is slightly useless. But before I got my new computer, my old one was very slow and would take around 10 minutes to get WoW fully started up in a major city, including loading the screen, mods, ect. And so this is for all you slow computer users out there.
As you all know, once you hit "Enter World" you cannot minimize until the bar is finnished loading. If you have a bad computer, sometimes your wow screen will freeze up after that making it even harder.
Log into your account, choose your character, then press "Enter World". Then on your keyboard press the "Start" button right after. This button will minimize your screen, but still keep your bar loading so you can use those 5-15 minutes browsing the web (MMowned included!), setting up music, talking on aim, and other things.
(Start up menu gives you options like log off, turn off computer, internet, games, programs, search, ect.)
If you did this right your Start screen in the bottom left corner should pop up, and WoW will be minimized.
The 'Start' button is located right under your Z key, or a few keys left from your space bar. Its got a little symbol on it that looks like a flag split in 4s.
This isnt exactly an exploit, so feel free to move it if you find a better place. =x I just knew it was useful for me, and thought it might be for others.