I read this very interesting article in the New Scientist today. Netflix announced a 1 million USD award to a team of scientists and mathematicians to improve an algorithm to recommend movies to users based on their past preferences. What' more, the algorithm must improve the firm's algorithm by 10%. The team worked with 100 million ratings of 20000 movies given by half a million viewers - now, that's a huge dataset.
And the competition was on since 2006 and it was finally awarded last week!! Such things fascinate me... I wish I had known about this competition:)