Cropping multiple pages at once

I print stuff, but I don't like wasting paper or ink. Research papers in PDF tend to be formatted for use in a journal. Chapters in PDF tend to be formated to use in a book. All have extra marginal whitespace. I found out today that OS X's Preview application can crop all selected pages at once. The steps are:
  1. Choose the View menu's Thumbnails
  2. Select all the pages in the sidebar. 
  3. Choose the Tools menu's Rectangular Selection item. 
  4. Select the rectangular region you want to keep. 
  5. Choose the Tools menu's Crop