PiPhone is a Raspberry Pi based phone designed by a software engineer David Hunt by combining a Raspberry Pi unit with a touchscreen, a GSM phone module and a battery. It was made as a part of a project to test the capabilities of Raspberry Pi mini computer.
The PiPhone can make and receive phone calls by using a SIM card. The total cost of all the components amount to $158 (£94). The PiPhone can only be used for the phone calls. Check out the PiPhone Demo in the following video :