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How a computer game helps Finland's National Library

20 June 2011 Last updated at 23:36 BST

One more step, and a tiny creature will cross the bridge and get to safety.

Just one more step - but letters do not match, the fragile structure blows up and the brown mole falls into a digital abyss.

Digitalkoot may sound like a typical online game - but there is more to it than just building bridges and saving moles.

Every time players complete a level, they help with a real-life task - digitising huge archives of Finland's National Library.

The video footage has been given to the BBC by the game's developer, a Finnish start-up Microtask.

Special report: The Technology of Business