<a href="http://casperelectronics.com/wp-content/uploads/Interfacing/ArduinoInterfacing.jpg"><img src="http://casperelectronics.com/wp-content/uploads/Interfacing/ArduinoInterfacing-282x300.jpg" alt="" title="ArduinoInterfacing" width="390" height="400" class="alignnone size-medium wp-image-858" /></a>
The schematic above illustrate 3 ways of interfacing various electronics, especially bent circuits, with the Arduino.
Each interface functions a little differently and can be useful.
<strong>-Variable resistor
-Digital Switch
-Digital to Analog convertor</strong>

Variable Resistor:
This 