http://osxdaily.com/2009/11/17/secrets-of-the-command-tab-mac-application-swi…

Command+Tab launches the application switcher, continue holding down Command and then try:

  • tab – move selection to the right in the app list
  • ` – move selection to the left
  • h – hide the selected application
  • q – quit the selected application
  • mouse scrollwheel – move the selection back and forth
  • left arrow – move selection to the left
  • right arrow – move selection to the right
  • up arrow – enter expose within the selected application
  • down arrow – enter expose within the selected application