Cell phones in Japan have evolved as a virtual extra appendage that people can't walk, ride or relax without, as they constantly peer into their screens, send and receive messages, play video games, watch TV, and sometimes even communicate verbally.

Since their debut here in 1979, mobile phones have become essential tools with more than 100 million subscribers.

Like many other things Japanese, the nation's cell phone culture has evolved differently than in other parts of the world, with special features and services so unique that the market has been likened to Ecuador's Galapagos Islands.