With what can you build a robot that can push things around, a robot that can flip and dance, a robot that can play cricket with you? What do you need to build robots that store your valuables, dispense candy, pick up objects and deliver them?

Well, your imagination, really.

To make things simpler, however, Lego Mindstorms have come up with the Robotics Invention System. With over 700 pieces of Lego, including the all-powerful RCX control system, you can build nine robots from the instructions, and many more from your own imagination. Though it requires a PC for the programming, it's fun to use and it's a great set for budding robotics experts.

There are three guided challenges with the set, and six pro challenges with the software. These include:

  • The "Roverbot", which is an explorer-type robot that moves slowly. You can program this robot to follow a line, or go where you want it to.
  • The "Acrobot", a fast acrobatic robot that flips. You can also program it to go backwards when it hits something, or to avoid darkness.
  • The "Inventorbot", a friendly robot that reacts when you shake his hand. You can program him to throw something, or to raise a hat when someone goes near him.
  • The "Deliverybot", which picks something up on a special stand and delivers it elsewhere.
  • The "Candy Sorter", which sorts Jaffa-sized lollies according to colour, and dispenses them.
  • The "Refrigerator Fred", which can tell whether the light is on in your refrigerator.
  • The "Security Vault", which guards your valuables and only opens when a card key with the right code is scanned.
  • The "Robotic Arm", which picks up objects, rotates and drops them off again.
  • Finally, the "Artbot", which can draw with three pens and sense lines that have already been drawn.

You can build many other robots with the power of imagination. I, for example, have built a very fast robotic car. But whatever the invention, there is no limit to what people can build... so if you have a set, enjoy it. It'll last.