USB Stealth Switch

The USB 'stealth switch' claims to be "the worlds first desktop cloaking device". From the GadgetLite blog:

This device can be hidden and controlled under your desk! With its 6″ USB cable, its foot tap button can be placed "hiddenly" under your foot. Once the foot tap is stepped, the following functions can be activated according to your preset options:

1. To switch or hide your current window/all windows instantly.
2. You can preset to bring up a preferred window at all times.
3. Password to protect your computer.
4. Mute sound, etc...

In other words, the 21st century version of the Boss-key.