It's amazing how far things have come. Raise your hand if you remember when encyclopedia salesmen used to go door to door, selling you a shelf of books for hundreds of dollars. Now you can have the Encyclopedia Britannica in the palm or your hand for $25. The Britannica Concise Encyclopedia 2010 has over 25,000 entries covering art, history, geography, politics, technology, science, sports, pop culture, and other subjects. It also has over 800 images and maps. And if you shake your iPhone, it brings up a random article.