This add-on will add an option to the Tools menu in the main window. When you select it, it will place all the cards in the currently selected deck into a web page, and show that web page in your browser. You can then use your web browser's print option to print the cards on paper.
The add-on should automatically open your browser with the generated web page, but if this does not work on your system, you can manually open the print.html file on your desktop.
Update 4 Mar 2022:
Update shortcut to avoid conflict (thanks to Abdo).
Updated 24 Feb 2020:
Update for Anki 2.1.20.
Updated 26 Aug 2017:
A new version for Anki 2.1. Should fix the page failing to open in the browser, and integrates the page break fixes posted in a comment. The Anki 2.0 version has not been updated at this time.
Updated Sep 1 2014:
Fix issues some users were having with the display of non-latin text.