Some sites have little icons of printers that say "Click here for a more printer friendly version" or "Click here to print this page". When you click on them it brings you to a page striped of most ads and the navigation bar and all non-essential items on the normal page.

How is this done? Do they actually write a second page for every page they have? Isn't that time consuming and somewhat annoying when you have to update two pages every time you just want to change something?

Or is this somehow acheived with server side scripting or the like?