Scratch

Scratch is a new programming language that makes it easy to create your own interactive stories, games, and animations – and share your creations with others on the web.
Scratch is developed by the Lifelong Kindergarten research group at the MIT Media Lab (http://llk.media.mit.edu). This is a fascinating software for children (or anyone else) to create, design and learn. With a very simple interface and instructions, it is easy to grasp. It allows children to play with characters, animation, sound, narrative and the concept of programming. I was introduced to this today, and have been experimenting ever since. Extremely addictive :)