: The UNDO button.
: In almost all editing programs PC users have been able to press
: "Ctrl+Z" ("Command+Z" on Mac) to undo their last
: actions. The continued press of this hotkey allows users to continue to
: undo until they've reached their desired earlier action. A simple but very
: useful hotkey that used like crazy by artist.

: However, Photoshop does not work this way by default. Instead, this commonly
: used hotkey only takes you back one action. Pressing it again oddly enough
: will undo your undo. This forcing artist to use a more complicated Undo
: hotkey to get the desired action.

... Pressing CTRL + ALT + Z (literally just holding down one more button) is how you continue undoing... It's better because you can use CTRL + Z to see differences between a change and the end result. This is extremely useful for PS's main purpose (the 'shopping of photos), but as I'm currently working on something art-related, I'm finding it an invaluable feature.

One you'll rarely use is CTRL + Shift + Z, which actually goes forward from any previous undo. Nifty to use when you pressed Undo too many times by accident.