I just discovered this by accident, figured I'd share.
In front of a word, ctrl + del = delete entire word. Behind it, ctrl + del = backspace entire word.
Another handy one for writers, to invert your screen colors:
Win7: Windows-+, then Windows--(minus), then Ctrl-Alt-i
Holy shit, Gordon, I love you. In, like, a totally not-weird way.
Maybe kinda weird.
Weird is the only way, really.
More Mac shorties: Most people know about Cmd-Tab (Alt-Tab on PC) to carousel through the application switcher, but did you know you can hit the accent key above it to reverse direction? When you've got as many apps open as I do, that's handy. Others for common special characters: