Thought you might be interested...
Download the latest version of Google Earth if you don't already have it - that's "version 4.2". You can get it free for PC and Mac at http://earth.google.com/.
Load up Google Earth as usual, click on the globe, and hold down CTL + ALT + A. This will bring up a dialog box allowing you to choose a plane, and a runway ... and get flying! If you have a Mac, press Apple + Option + A.
It's been discovered that some PCs require you to hold down CTL + WINDOWS + A instead of what we have above - so if it doesn't work first time, try the alternative keys.
The plane can be controlled by the keyboard. The full controls can be found at http://earth.google.com/intl/en/
userguide/v4/flightsim/index.html. It also works with mouse, joystick or plug-in joypad, like the one we used on the show.
Once you've activated it, the Flight Sim can be entered and exited through the Flight Simulator option in the TOOLS menu, allowing you to change plane and airport.