I was reminded this week while listening to some Merlin Mann of keyboard tricks that I use constantly. They work pretty much everywhere on the Mac.
Command* + right arrow = go to the end of the line of text (Windows: End key)
Command + left arrow = go to the beginning of the line of text (Windows: Home key)
Option + right arrow = go to the end of the word (Windows: Ctrl + right arrow)
Option + left arrow = you probably get the idea (Windows: Ctrl + left arrow)
Command + down arrow = go to the bottom of the page (Windows: Ctrl + End)
Command + up arrow = go to the top of the page (Windows: Ctrl + Home)
Option + down arrow = go to the end of the current or next paragraph ((Windows: Ctrl + down arrow)
Option + up arrow = go to the beginning of the current or next paragraph (Windows: Ctrl + up arrow)
Command + delete = delete the entire line
Option + delete = delete the current word
You can work some real magic here, jumping around the text you're working on without having to interrupt your typing. Anytime you can keep your hands on the keyboard, the better your speed and efficiency.
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* This is sometimes called the Apple key; it has the cloverleaf symbol on it.