A student ponders while drawing routes on a map of London in a test center in north London. All London black cab drivers are required to pass the Knowledge in order to be issued with a Hackney Carriage Licence. On average, between three and four years are needed to acquire this knowledge. A recent scientific study has shown that the area of the brain responsible for spatial memory, the hippocampus was significantly larger in taxi drivers. Aboard London taxis, drivers do not use GPS, they know the city by heart, preferring to rely on their memory rather than on modern technologies.

Locations are numbered on a map of central London in a Knowledge test center.

A student draws a route on a map of London in the test center.

The Google Street View snowmobile takes pictures of ski slopes for Google's Street View in front of the Matterhorn mountain in Zermatt, Switzerland on Feb. 21.

The Google Street View snowmobile takes pictures of ski slopes for Google's Street View in front of the Matterhorn mountain in Zermatt, Switzerland on Feb. 21.