In Connecting to Intel® Edison from Android* with Bluetooth* LE (BLE) describes a way to access BT via Arduino code but additional BT shield/kit is required.

Thorin Klosowski Cell phones are easy enough to come by these days, but if you've ever wanted to just build your own, Instructables user xiaobo__ shows how to do it with an Arduino.

Using a Nokia 1100, Tinkernut walks you through pulling apart the old phone, connecting it to the Arduino, and setting up the software required to make this sucker work.

A USB host shield for the Arduino is needed to connect to an Android hand set. You’ll be able to send and receive strings via the terminal, with support for carriage return and life feed characters.