Mac Productivity

Apple OSX General

Hide the dock. It's valuable screen space. At least move it to the left or right side, as vertical is more valuable.
Use Spotlight / Quicksilver to quickly open applications, search machine.
Paste plain text into email or anywhere with CMD+SHIFT+OPTION+v
Remap caps lock to CTRL.
Dashboard is neat - fix the weather widget moving with a hack.
Lock screen using Keychain access preferences.
Option button changes options on menus, for example, right click on item in dock, hold option to change menu items.
iStatMenus for system stats
Caffeine to prevent machine from sleeping
Screenshots using SHIFT+CMD+4 (or 1-3)
Emoji
Increase your key repeat rate in Preferences.
Use CMD+arrows to navigate end/home.
Use FN+arrows to pageup/pagedown.
Use Option+arrows to move word boundaries.
Highlight rapidly using SHIFT+ the above shortcuts.
Double click to select words.
Use CMD+(x/c/v) for Cut/Copy/Paste.
Use CMD+z for undo, normally CMD+y or CMD+SHIFT+z for redo.

Use multiple desktops to divide work & play, even projects.
Control + Up to activate Mission Control, but it's swooshy and annoying.
Use Total Spaces, which allows you to turn off animations for rapid desktop switching with CTRL+[num].
Assign applications to desktops.
Move applications by grabbing the title bar and switching desktop while still dragging, or you can use the Mission Control interface.
Finding wallpapers in Google

Divide an application into windows, position one on each desktop.
CMD+tab to switch application, OSX knows to switch to the open window on the current desktop.
Minimize is weak, use CMD+H to hide apps, CMD+[tab] to immediately go back to hidden app.
Use CMD+q to quit an app.
CMD+[tab] is powerful, you can quit apps, use the mouse, cycle forward and backwards, hit ESC. Works like a stack.
Position Windows using shortcuts, avoid dragging apps around. Use Moom.
Cycle through open windows in an app using CMD+`

CMD+SHIFT+[] for switching tabs. OSX allows you to override any application's shortcuts easily. Any app that doesn't support defaults can be added here.
CMD+num to select tab directly.
Use CMD+w to close a tab - works in any application.
Control dialogs with the CMD+s for 'Save' and CMD+d for discard. Tab and space to select.
Use Esc to cancel dialogs.

Filling out forms with the keyboard. Use TAB to move, arrow keys and letters to select state, space to accept.
CMD-T to open a new tab
CMD-SHIFT-T in browser to undo closed tab
CMD+L goes to the location bar (CMD+K in Firefox for search bar)
Tell the browser to remember your open tabs when closing.
Use favicons instead of verbose bookmarks to keep more favorites in bar.
Google calendar favicon shows current day of month.
Escape works on lightboxes.
CMD-click for opening a link in a new tab.
Use seperate browsers for work/home, keep Google cookies separate, any other accounts.
App tabs in browser allow you to pin your apps and have them in a predicatible place, to switch using CMD+num