A simple build that will plot the distance from the servo to an object in a sweeping motion, using Processing.
Attach an ultrasonic sensor to a servo, hook them up to an Arduino board.
This project consists of two parts
Sweeps the servo back and forth. After every step, it will read the distance off the ultrasonic sensor and write the value to Serial.
Listens for "readings" (off the Serial port) from the Arduino and plots the result with simple graphics.
You can read more about Processing here.