Many of us would like to swap the direct print button on Canons for a mirror lock up button but in the mean time here's a quick way to initiate it (sure plenty of people have worked this out but I'd never seen it written anywhere so thought I'd share with those who haven't spotted it yet).
Set your camera to whichever settings you most often use when using mirror lockup (Manual, ISO 100, etc, etc.) plus set mirror lock up, then go into your menu and save user settings as Custom (or Custom 1, 2, 3). Now when you want mirror lock up turn your mode dial to C and mirror lockup is ready set without diving into menus.
It's not perfect as you might not always want to be in manual, ISO 100, etc but I find it fairly handy most of the time.
Tom