With all the offshoots from outside developers that have expanded the functionality of free Google-branded products like Google Maps, here's another cool tool that I'm surprised nobody launched before: Goggles, a Google Maps flight simulator.

One of the beautiful things about Google is that they have made their application open so developers using the AJAX language can create cool applications like this free game that interacts with real world objects.

This ingenious variation of Google Maps lets you fly over 19 of the world's major cities as well as the Moon and Mars, using your arrow keys to control an animated plane over streaming satellite images from Google Maps. You can turn as well as adjust altitude for a full flying experience.

A detailed guide also shows how you can link a specific start position -- perhaps your home or business -- to Goggles via Firefox. Although Goggles is still in the beta phase, it works well on Windows and Macintosh computers.