Hey, I never found this trick for Microsoft office. Pretty cool! Why I try to look for a shortcut for the strikethrough operation? Generally speaking, I make a get things done list (actually a to-do list) everyday, and when I finish one of the items in the list, I used strikethough it to mark it as completed.
And here is another trick I never thought MS will provide till these days, it is about the text editor in Visual Studio, the rectangle select. I used to do this select in the asp times with editplus. This operation is pretty useful when your code aligned well, for example, by the equation sign. VS also support this, just hold alt key when you drag your mouse. Otherwise, if you don’t want to use mouse drag, just press ctrl+alt, and then press any arrow key.