It amazes me how many people are amazed when I show them this little trick. Holding the "Alt" key while clicking and dragging allows one to select a rectangular region in word. When using a monospace font (fixed-width fonts like Consolas or Courier New), this can be used to quickly delete columns of text. Best results are achieved using monospace fonts, but this tool has helped me many times in other situations. An example of a rectangular region selected with this technique is below.
Sometimes I will launch Word just to use this tool and go back to editing files in another program. I learned this back in high school in what I thought would be a gimmicky course on Microsoft Office. In that course I learned some pretty useful skills that, while not making me an expert, have served me well. It amazes me how many people have taken courses centered around Microsoft Office and still seem perplexed by it.