Mac OS X keyboard shortcuts

Start up hot-keys (press key while booting)

X = Force Mac OS X startup
C = Start up from a bootable CD
N = Attempt to start up from a compatible network server (NetBoot)
T = Start up in FireWire Target Disk mode
Opt-Cmd-Shift-Delete = Seeks a different startup volume
Shift = Start up in Safe Boot mode
Cmd-V = Start up in Verbose mode
Cmd-S = Start up in Single-User mode

Cmd-Opt-Esc = Force Quit menu
Cmd-Opt-D = Show/hide the dock
Ctrl-Eject = Bring up Shutdown/Sleep/Logout Dialog
Ctrl-Cmd-Eject = Restart immediately

Clipboard

Cmd-C = Copy
Cmd-V = Paste
Cmd-X = Cut
Cmd-A = Select All

Finder Navigation

Cmd-N = New Finder window
Cmd-W = Close Window
Opt-Cmd-W = Close all Windows
Cmd-Down = Open File/Folder
Cmd-Up = Navigate to parent
Cmd-Right = Expand folder (in list view)
Cmd-Left = Collapse Folder (in list view)
Opt-Cmd-Right = Expand folder and its subfolders (in list view)
Opt-Cmd-Up = Open parent folder and close current window
Cmd-Shift-H = Jump to your Home folder
Cmd-Shift-A = Jump to your Applications folder
Cmd-Shift U = Jump to your Utilities folder
Cmd-Shift K = Jump to the Network browser
Cmd-Shift G = Goto Folder…
Cmd-1 = View as Icons
Cmd-2 = View as List
Cmd-3 = View as Columns
Cmd-Space = Open Spotlight (OS X 10.4)
Cmd-Delete = Move file/folder to trash
Cmd-Click window title = Display the file path

Menu Commands

Shift-Cmd-Q = Log out
Shift-Opt-Cmd-Q = Log out immediately
Shift-Cmd-Delete = Empty Trash
Opt-Shift-Cmd-Delete = Empty Trash without dialog
Cmd-H = Hide window
Opt-Cmd-H = Hide Others
Cmd-N = File New window
Shift-Cmd-N = New Folder
Cmd-O = Open
Cmd-S = Save
Shift-Cmd-S = Save as
Cmd-P = Print
Cmd-W = Close Window
Opt-Cmd-W = Close all Windows
Cmd-I = Get Info
Opt-Cmd-I = Show Attributes Inspector
Cmd-D = Duplicate
Cmd-L = Make Alias
Cmd-R = Show original
Cmd-T = Add to Favorites
Cmd-Delete = Move to Trash
Cmd-E = Eject
Cmd-F = Find
Cmd-Z = Undo
Cmd-B = Hide Toolbar
Cmd-J = Show View Opts
Cmd = [ = Go Back
Cmd = ] = Go Forward
Shift-Cmd-C = Go to Computer
Shift-Cmd-H = Go to your Home folder
Shift-Cmd-I = Go to iDisk
Shift-Cmd-A = Go to Applications folder
Shift-Cmd-G = Go to Go-To Folder
Cmd-K = Connect to Server
Cmd-M = Minimize Window
Cmd-? = Open Mac Help
Cmd-Space = Open Spotlight (OS X 10.4)

Screen capture

Cmd-Shift 3 = Capture the screen to a file
Cmd Ctrl Shift 3 = Capture the screen to the clipboard
Cmd-Shift 4 = Select an area to be captured to a file
Cmd Ctrl Shift 4 = Select an area to be captured to the clipboard
Cmd-Shift 4, then press Space = Capture entire window

Universal Access

Opt-Cmd-* (asterisk) = Turn on Zoom
Opt-Cmd-+ (plus) = Zoom in
Opt-Cmd– (minus) = Zoom out
Cmd-Opt-Ctrl-8 = Invert Screen colours

Window Management

Cmd-W = Close window
Cmd-Opt-W = Close all windows
Cmd-M = Minimise window
Cmd-Opt-M = Minimise all windows
Cmd-H = Hide Application
Cmd-~ = Cycle through windows for current application
Ctrl-F4 = Cycle through every open window
Cmd-Tab = Bring up the Application Switcher.
Cmd-Tab = Cycle Forwards
Cmd-~ = Cycle Backwards
Cmd-Shift-Tab = Cycle Backwards
Cmd-Q = Quit application

Expose

F9 = Show all open windows on the screen at once
F10 = Show all windows for the current application.
F11 = Shows Desktop
F12 = Activates Dashboard
F12 (hold) = ejects disk

Miscellaneous

Opt-Cmd-D = Show/Hide Dock
Ctrl-Up = Move up one page
Ctrl-Down = Move down one page
Opt-Drag = Copy to new location
Opt-Cmd-Drag = Make alias in new location
Cmd-Drag = Move to new location without copying
Opt-Cmd-Eject = Sleep
Cmd-click window toolbar button (upper right corner) = Cycle through toolbar views
Ctrl-Cmd-D and mouse over word in Cocoa applications = shows Dictionary description for that word