Kidz, if you haven't downloaded and tried out the new 5.0 version of Google Earth I heartily encourage you to do so. Sure, you can skim around our planet and zoom in on your neighborhood. You can go look at the pyramids in Egypt, too. Meh.
This new version allows you to run around on Mars. Simply click on the planet icon in the top toolbar and select "Mars". Go into flight simulator mode and fly an F16 around the landscape. To see the travels of the Mars Rovers, select the "Mars Gallery" layer, open it, and select "Rovers and Landers" and click on the rover of your choice. Click on one of the camera icons to see high resolution pictures that have been taken by the rover. It's amazing.
But wait there's more. Just as the Googley engineers are plying the heavens, they are also looking to the depths of the sea. Go back to Earth (click on the planet icon in the toolbar and select "Earth"). Select the oceans layer. Explore shipwrecks, National Geographic featured sites, and view Cousteau's adventures beneath the sea. You've got to like this.