Wii Knock or Cheap Arduino Bluetooth

This use of the Wooduino has a Wiimote attached to the board with some screw and Vex parts, along with a piezo buzzer being used as a knock sensor. When the Arduino gets a knock reading from the piezo it uses a servo to press the A button on the Wiimote. If you only need one bit of information it could be a cheap bluetooth connection for the Arduino. Or if I can get a microphone connected to the Arduino an easy way to use the Wii Fit without holding the controller.