Finally, an answer for all my 9-to-5 pals looking for a way to discretely make the most of their time at the office:

Ghostzilla
Surf the Internet freely, knowing that people around you cannot see the Web browser on your screen even if they look directly at it!

What I like best is their “Using Ghostzilla” page:

Use Ghostzilla … to learn, read news, and stay informed. Use it at times when you would otherwise be unproductive anyway. Most environments expect people to spend more time in the office than they can physically be productive. Use Ghostzilla to fill that gap with knowledge about science, culture, finances, sports… anything you like to make the best of your time. [via MeFi]