• Move your cursor between words: alt + Left or Right Arrow Key. This lets you jump between words in a sentence. This is helpful when you find that you mistyped a word earlier in a sentence, and you don’t want to use your mouse to move your cursor to the right spot.
• Move your cursor between paragraphs: alt + Up or Down Arrow Key. This lets you jump to the beginnings and ends of paragraphs, and is very useful when navigating large amounts of text.
• Delete the previous word: alt+delete. If you want to delete the last word you typed, this combination is handy.
• Delete the next word: alt+forward delete (fn+delete on laptops). Similar to the previous tip, this deletes the word in front of your cursor.

Do you have any other text navigation tips?

Update: Added the paragraph navigation tip.

Mac Tip: Navigate Text by Word is a post from brandon martinez.