The perfect rectangle - which is around the size of Wales - was noticed on the search giant's underwater exploration tool by an aeronautical engineer who claims it looks like an "aerial map" of a city.

The network of criss - cross lines is 620 miles off the coast of north west Africa near the Canary Islands on the floor of the Atlantic Ocean.

The underwater image can be found at the co-ordinates 31 15'15.53N 24 15'30.53W.

Computers controlled by the mind are going a step further with Intel's development of mind-controlled computers. Existing computers operated by brain power require the user to mentally move a cursor on the screen, but the new computers will be designed to directly read the words thought by the user.

Google on Thursday further embraced the world of tweets, status updates, and on-the-fly posts with a website devoted to finding "real-time" content as it hits the Internet.

A search engine being rolled out in 40 countries at google.com/realtime builds on features that the Internet powerhouse has been adding incrementally to its online query service.

"Real time content is often one of the best sources of information about what is happening right now," Google product manager Dylan Casey told AFP while introducing the new real-time search home page.

"We are giving people more tools to drill down into these results."

In the same manner that Google has search pages devoted to pictures or videos, the new one is tailored to comments, images or other public content fired off at online social networks such as Twitter, Facebook, or MySpace.