Are you afraid that one of these days your boss is going to catch you while you're browsing the websites on firefox? There's a solution for this. Panic is [firefox extension] like the perfect boss key for Firefox. It will not just prevent you from getting into an embarrassing situation but boss may even leave your office cubicle totally impressed. It is called the Panic extension because it will save your butt just in case the boss sneaks up on you.
To give boss an impression that you weren’t wasting time, you can configure Panic to replace all open tabs with a single work-related website like your company’s intranet homepage or any other web page.
Credit: Close All Websites in Firefox Before Boss Approaches the Cubicle