The Hybrid Brick Sorter - NXT 2.0 Discovery Book update
This is one of the robot projects that you can build with "The LEGO MINDSTORMS NXT 2.0 Discovery Book - A Beginner's Guide to Building and Programming Robots".
The Hybrid Brick Sorter sorts LEGO bricks by four colors and two sizes. Chapter 14 in the book will tell you all about this robot: how it identifies a bricks color and size; how to build it and how to program it. You'll also find various challenges to further expand on the robot program and design.
Learn more about the book here, or pre-order the book here. It will be available in April.