From the BBC:

A giant “digital cloud” that would “float” above London’s skyline has been outlined by an international team of architects, artists and engineers.

The construction would include 120m- (400ft-) tall mesh towers and a series of interconnected plastic bubbles that can be used to display images and data.

The Cloud, as it is known, would also be used an observation deck and park.

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Its designers plan to raise the funds to build it by asking for micro-donations from millions of people.

“It’s really about people coming together to raise the Cloud,” Carlo Ratti, one of the architects behind the design from the Massachusetts Institute of Technology (MIT) told BBC News.

“We can build our Cloud with £5m or £50m. The flexibility of the structural system will allow us to tune the size of the Cloud to the level of funding that is reached.”

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The different spheres would act as structural elements, habitable spaces, decoration and LCD screens on which data could be projected.

“We could provide a custom feed of… searches made by Londoners during the Olympics to give a real time ‘barometer’ of the city’s interests and mood,” said Google, one of the supporters of the project, which has also offered to provide the information feeds.

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The structure would also be used to harvest all the energy it produces according to Professor Ratti.

“It would be a zero power cloud,” he said.

As well as solar cells on the ground and inside some of the spheres, the lifts would use regenerative braking, similar to that in some hybrid cars.

That way, the designers say, potential energy from visitors to the top of the tower can be harnessed into useful electricity.