For all intents and purposes Crash Planning looks like a really boring calendar program. But in reality it's a fun, casual puzzler in which you have to group same-colored blocks to make them disappear. Mwahaha!

Developed back in the naughts as a viral marketing game, Excit is now available online, for free. In the puzzle game, you have to escape the spreadsheets. It'll easily kill that looooong half hour before clocking out.

Anyone who casually glances at your screen will think you're Googling something important for work, but in this game you'll actually be guessing search terms based on the results shown. It's strangely addictive.

In the spirit of Atari's Breakout, Breakdown has you use a paddle to disappear text from a Word doc. Cunningly, you can hit the space bar to kill the gaming elements if anyone comes too close to your display.

Therapeutically simple, just steer the sheep into the pen. Thanks to the Excel design, from a distance it'll look like you're corralling numbers.

As long as you turn down the sound, you can play to your heart's content. Google's Pac-Man Doodle offers fully-functional search during gameplay. If the boss approaches mid-game, just start looking up some boring company-related data.

Like the popular Lunar Lander games of old, this has you steer a teeny-weeny rocket safely through jagged bar graphs.

The Email Game gamifies your Gmail inbox, encouraging you to clear your inbox down to that mystical "zero" status we all dream about. Productive and fun!

Combine colors to keep the blocks low. It's just like doing accounts, but much, much more fun.

Finally, if you like to get competitive, a typing test can be a fun way to while away a spare 10 minutes. And if you do get caught, at least you can argue that you're improving your keyboard skills!