can't let these danged computers do everything for us!

With more and more information being digital, I find that I'm often using combinations of email reading, word processing, web browsing, pdf viewing, cad modeling (ad nauseum) software simultaneously. An example: Email comes in with a pdf attached. I read the email and open the pdf, referring back to the email for context. Then I can compare the info in the pdf to something I'm working on in my publishing software. With two screens, it's easy to have these all open and visible, enabling quick comparison and transferring of information.