Command Shift Q

⌘ – Command ( Key)
⇧ – Shift Key
⌥ – Option Key
CTRL – Control Key

General:

⇧ + ⌘ + U – Open Utilities folder in Finder and Save / Open dialogue
⌘ + ⌥ + T – Opens special text characters float-over box in any Cocoa application
⌥ + ⌘ + T – Hide Toolbar / Show Toolbar in Finder windows
⌘ + T – Add highlighted items to Finder sidebar
⌘ + 4 – View Finder in Cover Flow
⌥ + ⇧ + ⌘ + Delete – Empty Trash without confirmation dialogue
⇧ + Control + ⌘ + 4 – Capture a selection to the Clipboard
⇧ + ⌘ + C – Display the Colours float-over box
CTRL + ⌘ + C – Copy the formatting settings of the selected item and store on the Clipboard
⌥ + ⌘ + F – Move to the search field, i.e., google toolbar in Safari, search field in iTunes or Spotlight in Finder
⌘ + J – Scroll to a selection
⌥ + ⌘ + M – Minimize all windows of the active application to the Dock

iTunes

CTRL + ] (close square bracket) – Go to the next page in the iTunes Store
CTRL + ⌥ + ← or → – Move forward or backward within a song
⇧ + ⌘ + N – Create a new playlist with the selected songs
⌘ + R – Show where a song file is located
⌘ + L – Show the currently playing song in the list

Dock

⇧ + click & drag Dock Separator to move the Dock from the bottom, left and right side of the screen
⌥ + click & drag Dock Separator to ’snap’ between commonly used icon sizes
⌘ + drag & drop an item to the Dock without existing icons ‘dodging’ out of the way. Useful for forcing an application to Open With.

Adding and removing icons to and from Finder windows:

Adding and removing icons to and from OS X Finder windows from Jim Gardner on Vimeo.