Like to play a quick game while at work? Unless you have a strategically-positioned cubicle, it's usually not that easy. Sure, you might get away with it every now and then. Chances are good that you'll eventually be caught, though.
If your desire for mindless distraction overwhelms the need for job preservation, you should head on over to CantYouSeeImBusy.com for a solution. With games that are carefully masked as regular office software, you can waste an entire day on their offerings. Seriously, it's your best chance to slack off without leaving your supervisor any wiser to it.
The current offering consists of three games, namely Leadership, Breakdown and Cost Cutter. Leadership has you commanding a ship that travels across a series of Excel graphs, with the goal of steering it to a landing area without hitting any of the edges. Breakdown has you controlling a perpetually bouncing ball in order to clear blocks of text inside a Word-like document. Cost Cutter is a two-in-a-row puzzle game that looks completely like a professional chart.
You can have your organization's title displayed throughout the entire game, so it looks like an official company document. If the boss comes around for a visit, simply hit the space bar and all the game elements will disappear, leaving only the filled-out documents in front of you. Just make sure to have a canned explanation about what you're doing (e.g. "I'm researching business statistics" or whatever) to get them out as fast as possible.