Amateur astronomy may very well be the most popular and quickly growing scientific hobby in the world today. This popularity undoubtedly has a basis in the fact that astronomy covers a lot of "turf". Meanwhile the existence of the Internet has made it possible for observers to share their love and knowledge of the sky while working together and advancing the state of the art. Finally, the fact that telescopes and binoculars are so readily available in great diversity of cost, quality, and capacity doesn't hurt either.