If you were thinking, "Those guys at Google are going to pack in a secret flight simulator into the new edition of Google Earth," pat yourself on the back, as that is exactly what they have done.Apparently, the latest version of Google Earth has an easter egg: a flight simulator. It's not quite like Microsoft Flight Simulator, but it's a promising start.
How to see this feature. Make sure you have Google Earth 4.2. Open the application, click on the globe and then press Ctrl+Alt+A. You should see this dialog that lets you choose one of the two aircrafts (F16 "Viper" and SR22) and an airport.
Here's the initial view from London Heathrow Airport:
... and here's a nice view from Kathmandu:
To fly, you need to read this list of keyboard shortcuts, but you can also use a mouse or a joystick. "To disable or enable mouse controls, left click (single click on a Mac). Once mouse controls are active, the pointer shape changes to a cross on your screen."
Marco Gallotta, who found this feature, has some tricks: "Moving on though, you can get a quick start by holding Page Up for a few seconds to increase to maximum thrust (thrust meter is the left bar of the lower-left meters). Once you've accelerated to a sufficient velocity use the arrow keys to take-off. The keys are in reverse as one would expect with any flight simulator, so use the down arrow to take-off. When you've gained enough altitude then stabalise the aircraft to a straight flight path. It can be rather tricky to get the hang of as the controls are quite sensitive."
This easter egg could become a standard feature in the next versions of Google Earth and it will bring even more fun to the application.