Some people say Wagon Wheels are smaller now than they were when you were a kid and, in truth, it seems that most things have got smaller as you have got bigger. Something that has reversed the trend, though, is the work of those clever people at Lego, which just seems to have got bigger, better and more diverse as the years go on. Now, with Lego Mindstorms, they seem to have surpassed even themselves, by venturing into the formerly uncharted territory of programmable plastic bricks.

With a staggering 700 building components in the box - we're reluctant to call them bricks as they include tubes, wings, bands, wheels and all manner of strange and unusual attachments - this is a mammoth set. Delve a little deeper and you'll find yourself coming across light sensors clever enough to know the difference between red and blue, and pressure gauges with built-in switches to make your creations turn or move on their own.

Perhaps the most important and impressive bricks, though, are two large blocks bigger than the rest: these are the driving force behind Mindstorms.

The first, shaped somewhat like the nose cone of a NASA Shuttle, attaches to your PC's COM port. The second, a more conventional rectangular shape, is the basic block around which you will build your models. Each sports an IR device - transmitting on the nose cone and receiving on the block - that allows you to program the actions of your creations using the simplistic drag-and-drop PC software.

Once you have "constructed" your commands on-screen in much the same way that you build your model by putting subroutine bricks on top of one another, it can be transmitted to the model and, because it is written to the remote memory, the PC can be turned off. Stored in the receiving brick, it can now be activated using the four buttons on top of your model.

If this all sounds a bit intimidating, an extensive set of animated tutorials will take you through everything from installing the batteries to completing your first model, a scaled-down version of the Mars Pathfinder buggy.

Leading you through one brick at a time and showing exactly how each should be attached, it then moves on to the rather more important matter of how you tell the model exactly what you want it to do.

Of course, every brick in the Lego range is a standard size, which means that when you've exhausted the possibilities offered by the basic kit you can add to it to create an infinite number of possibilities. Two eight-stud bricks can be joined in no less than 24 different ways. Add another, and a total of 1,060 connection possibilities present themselves. With such a large set, we sometimes found it difficult to find what we were looking for. Although the pieces were sorted into a semi-logical collection of bags, it still took us a good ten minutes to find the sensor bricks, even though we knew exactly what we were looking for. We also found the software's insistence that we complete the training sessions before being let loose on the programming language a little irritating: we would have liked to be able to get straight into the product and use it.

According to Lego's web site, which also explains that in Latin the word Lego means "I put together", Lego bricks are played with by more than 300,000,000 children in 130 countries. With the arrival of Mindstorms, we feel it's time to redress the balance. Over ten years of development in partnership with MIT have made this set too much fun to be confined to the kids' bedroom. If you don't have children of your own, pop out and borrow a few, then take them with you when you buy the set: you'll feel less embarrassed. But whatever you do, don't let them get hold of it - you'll never get it back.

PRICE #160 (#136 ex VAT)

CONTACT Lego 0845 606 2043 www.legomindstorms.com

GOOD POINTS Innovative, extensive, endless fun.

BAD POINTS Difficult to find pieces. Bossy software.

CONCLUSION Guaranteed to bring out the kid in everyone.

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