Sparkfun Inventor's Kit Circuit-13

// Based on File > Examples > Servo > Knob
// Controlling a servo position using a potentiometer (variable resistor)
// by Michal Rinott <http://people.interaction-ivrea.it/m.rinott>

#include <Servo.h>

Servo myservo;  // create servo object to control a servo

int potpin = 0;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin

void setup()
{
  Serial.begin(9600);
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop()

{
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  Serial.println(val); 
  val = map(val, 50, 300, 0, 179);     // scale it to use it with the servo (value between 0 and 180)
  myservo.write(val);                  // sets the servo position according to the scaled value
  delay(15);                           // waits for the servo to get there
}

map(value, fromLow, fromHigh, toLow, toHigh)
For full details on how it works: http://ardx.org/MAP
To calibrate the sensor we use the debug window (like in CIRC-11). Open the debug window then replace the fromLow value (default 50) with the value displayed when the sensor is unbent. Then replace the fromHigh (default 300) value with the fully bent value.
                  
void loop()

{
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  Serial.println(val); 
  val = map(val, 269, 140, 0, 179);     // scale it to use it with the servo (value between 0 and 180)
  myservo.write(val);                  // sets the servo position according to the scaled value
  delay(15);                           // waits for the servo to get there
} 

One player rock paper scissors glove:  http://ardx.org/RPS
Electronic plant brace: monitor if your plant is bending towards light and fix it: http://ardg.org/BRACE