Mac OS X Lion: Shortcuts to open Mission Control

• Use Touchpad: swipe up with 3 or 4 fingers
• Use Magic Mouse: double tapping the mouse surface
• Use Mac Keyboard: Dashboard key (F3 on my MacBook Pro)
• Find Mission Control app from Applications and keep it in Dock
• Find Mission Control app using Spotlight

See Also: http://www.tuaw.com/2011/07/20/mac-os-x-lion-and-mission-control/