In my opinion, mobile phones are the necessary devices nowadays. 90 percent of people can not leave home without them. This is no accident. It is the easiest and fastest way to communicate at a distance. Person just need to select the number and press the call. Unlike the past, when we had to write a letter or go to special telephone center. Also, modern phones have a camera, maps, access to the internet, music player, alarm and etc. And all of it in one small thing which we can always be with human. It is very convenient especially for a person who lives in the big city.