Mobile phones

A mobile phone is a device that can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network. By contrast, a cordless telephone is used only within the short range of a single, private base station.
All mobile phones have a number of features in common, but manufacturers also try to differentiate their own products by implementing additional functions to make them more attractive to consumers. This has led to great innovation in mobile phone development over the past 20 years.
The common components found on all phones are:
Some featues of mobile phones

• Roaming: which permits the same phone to be used in multiple countries, providing that the operators of both countries have a roaming agreement.
• Send and receive data and faxes: (if a computer is attached), access WAP services, and provide full Internet access using technologies such as GPRS.
• applications like a clock, alarm, calendar and calculator and a few games.
• Sending and receiving pictures and videos through MMS, and for short distances with e.g. Bluetooth.
• GPS receivers integrated or connected (i.e. using Bluetooth) to cell phones, primarily to aid in dispatching emergency responders and road tow truck services. This feature is generally referred to as E911.
• Push to talk, available on some mobile phones, is a feature that allows the user to be heard only while the talk button is held, similar to a walkie-talkie.

Bluetooth:
Bluetooth is wireless connectivity. In other words, it is a way of connecting mobile phones to other mobiles phones and devices without wires. Using radio waves similar to a remote control toy, Bluetooth has a range of up to 50 metres depending on the particular Bluetooth device and the prevailing conditions.
Typical examples are connecting a Bluetooth headset or car kit to your Bluetooth mobile phone. Simply jump in the car, switch on the ignition and your Bluetooth mobile phone will automatically connect to the Bluetooth car kit with not a wire in sight - simple, quick and very convenient.

Refrences:
http://en.wikipedia.org/wiki/Mobile_phone
http://en.wikipedia.org/wiki/Mobile_phone_features
http://www.mobiles.co.uk/bluetooth-mobile-phones.html