This is really neat, possible fun activity for the classroom.
Open Google Earth.
Click on the globe.
Hold down control and alt and hit the letter A to enter flight
simulator mode.
Control and H will give you all the controls.
Enjoy your flight.
Next time you open Google Earth you can go to tools--> Flight
Simulator
Directions for the Mac can be found here:
http://earth.google.com/intl/en/userguide/v4/flightsim/index.html