Game for the Blind?

This has to be the most bizarre form of public service I've ever heard of:

Researchers at Carnegie Mellon University (CMU) in Pittsburgh, Pennsylvania, have designed an online game that aims to harness players’ brainpower to help make websites more accessible to blind people.

Visually impaired people often use text-to-speech converters called screen readers to listen to the content of web pages spoken by a synthesised voice. However, the pictures on most websites remain inaccessible because very few have detailed captions to accurately describe them.

The online game "Phetch", which will be made available at http://www.peekaboom.org/phetch/, is designed to encourage other web users to generate these missing captions. Played in groups of three to five people, it randomly assigns the role of "describer" to one player; the rest become "seekers".

'nuff said.