I think there was a HUD thread around before but I've noticed that a lot of players have their hotbars set up so they make kind of "U" in the lower center of the screen. It means they have to be watching what is going on and all the buttons are clustered near each other. I think this assumes you are clicking on the skills though. That obviously wouldn't work with the crossbars and would take a lot of time to set up to use with hotkeys.
