Walk through the "black art" of cryptography, including public/private and symmetric encryption, hashing, digital signatures, and a dash of salt.

Google Earth combines satellite imagery, maps and the power of Google Search to put the world’s geographic information at your fingertips. Fly from space to your neighborhood. Type in an address and zoom right in. Search for schools, parks, restaurants, and hotels. Get driving directions. Tilt and rotate the view to see 3D terrain and buildings. Save and share your searches and favorites. Even add your own annotations.