Apart from having lots of fun you can also use LEGO as a medium for rapid protoytyping or holding various parts of a project together. One neat example of this has been demonstrated by Mathias Leroy whose Arduino-controlled demonstration of a solar tracker is integrated with the toy bricks.
The device has a light sensor on each corner of the square base - and the Arduino constantly measures the values from each sensor with which it can determine the direction of the strongest source of light - then rotates the "panel" using the two servos. This would be fun as a demonstration of a real solar tracker for a school science project or even adding to your own LEGO layout. Check out the following video for a quick demonstration:
For complete instructions to make your own version, visit the project page. And for more, we're on facebook, Google+, and twitter - so follow us for news and product updates as well.
If you're looking to learn about Arduino development platform and how it interacts with external devices such as servos and light sensors - you can't go past "Arduino Workshop - A Hands-On Introduction with 65 Projects” by John Boxall.
Arduino Workshop takes the reader from having zero knowledge about the Arduino platform, electronics and programming and leaves them with the know-how and instructions on everything from blinking an LED, to robotics, wireless data, cellular communications, motor control, sensors, Internet connected systems and more. For more information including a sample chapter and table of contents, visit the book page.
