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 on-line game "Phetch", which will be made available at http://www.peekaboom.org/phetch [although not yet], 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".

The game then serves up a randomly chosen website image to the describer, who has to write a pithy short paragraph about it. The words are then sent to the seekers, who use search engines to hunt down the correct picture on the web. The first seeker to find the image becomes the describer in the next round.