The other two machines used colour-coded slips of paper and chips of wood to represent information.

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By one estimate, last year Indians spent more money on gold than on cars, two-wheeled transport, fridges and colour televisions combined.

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By using the latest in rear-projection technology, a high resolution, colour 3D-like holographic image is projected onto a flat two-dimensional sheet of acrylic in the shape of a woman.

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The lighting, camera angles, wall-colour, acoustics and furniture are all designed to make two Halo systems feel like a single room when linked together, and to do away with the 15 minutes of messing around usually required to set up videoconferencing gear.

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