This is posted from an OS X help email that I receive daily.
Shift-Command-Q - Apple Menu - Log out
Shift-Option-Command-Q - Apple Menu - Log out immediately
Command-H - Finder Menu - Hide Finder
Option-Command-H - Finder Menu - Hide Others
Option-Shift-Command-Delete - Finder Menu - Empty Trash without dialog
Shift-Command-Delete - Finder Menu - Empty Trash
Command-A - Edit Menu - Select All
Command-C - Edit Menu - Copy
Command-V - Edit Menu - Paste
Command-X - Edit Menu - Cut
Command-Z - Edit Menu - Undo
Command-D - File Menu - Duplicate
Command-E - File Menu - Eject
Command-F - File Menu - Find
Command-I - File Menu - Get Info
Command-L - File Menu - Make Alias
Command-N - File Menu - New Finder window
Command-O - File Menu - Open
Command-P - File Menu - Print
Command-R - File Menu - Show original
Command-T - File Menu - Add to Favorites
Command-S - File Menu - Save
Command-W - File Menu - Close Window
Command-Delete - File Menu - Move to Trash
Shift-Command-S - File Menu - Save as
Shift-Command-N - File Menu - New Folder
Option-Command-I - File Menu - Show Attributes Inspector
Option-Command-W - File Menu - Close all Windows
Command-1 - View Menu - View as Icons
Command-2 - View Menu - View as List
Command-3 - View Menu - View as Columns
Command-B - View Menu - Hide Toolbar
Command-J - View Menu - Show View Options
Command-K - Go Menu - Connect to Server
Command - [ - Go Menu - Back
Command - ] - Go Menu - Forward
Shift-Command-A - Go Menu - Applications
Shift-Command-C - Go Menu - Computer
Shift-Command-F - Go Menu - Favorites
Shift-Command-G - Go Menu - Goto Folder
Shift-Command-H - Go Menu - Home
Shift-Command-I - Go Menu - iDisk
Command-M - Window Menu - Minimize Window
Option-Command-M - Window Menu - Minimize All Windows
Command-? - Help Menu - Open Mac Help
ENJOY !!