If you've ever dreamed of being able to fly through the air without an airplane, you will love Google Earth, a 3D geographical program.

You can go anywhere in the world and see what it looks like from the air. Actual satellite imagery is projected onto virtual 3D surface so you can fly through the mountains, across deserts and over oceans in proper perspective.

You can create sets of places and automatically tour them. You can see notes others have made of interesting places and view their photographs taken at ground level. You can share your own notes with others. If you fly high enough, you can even see the stars.

Google Earth for the Mac is free and can be downloaded here. All you need is a fairly modern computer and a broadband internet connection, not dial-up.

Be warned that you may end stay up all night going on adventures and viewing the sights, trying to find all your favorite places, reliving past adventures and planning for new ones.