I found this on the interweb somewhere. If you have the newest version of Google Earth, give this a try:

A hidden feature in version 4.2 is a flight simulator, that lets you fly over the Google Earth landscape. Admittedly it is not the best sim ever, if you are one of those people that gets excited about drag factors and so on. (If you think drag factor is something to do with wearing womens clothing, relax, you are not one of them.)

Load up Googley Earth, and then press either:

Windows - CTRL + ALT + A (Capital A)

Command / Open Apple key + Option + A (Capital again)

I haven’t had chance to try it on Linux as yet, I will later. You may have to try several times, it is not that responsive. You will know when it has worked as you will get this:

Set it how you want, a word of advice though do not choose the F16 unless you can really fly one. It is a little sensitive. Arrow keys, joystick or mouse work. I also found “G” for landing gear, “F” puts the flaps on, and Page up and Page Down change the speed.

http://earth.google.com/intl/en/userguide/v4/flightsim/index.html A basic manual and description of the keys.

http://earth.google.com/ To download Google Earth

Have fun.