Windows, Linux and Mac: Print Context Menu is a Firefox extension that adds the Print and Print Preview options to the context menu of your Firefox browser. That’s all.
This little extension adds to Firefox’s right-click menu a feature that most other browsers like Opera, Internet or Google Chrome have out of the box.
Anyway power Firefox users do ctrl+p to get the printing started and when ever they need the Print Preview they hit alt+f, then v
Print Context Menu is a free download for all platforms with Firefox
via [How-To Geek]