/*
 the Dawn Treader
 (Jim is having too much fun with legos.)
 */

int motor_pin_right = 9;
int motor_pin_left = 11;

int speed[] = {0, 127, 255};

int fast = 2;
int slow = 1;
int off = 0;

void warp_factor(int left, int right, int sec){
  analogWrite(motor_pin_left, speed[left]);
  analogWrite(motor_pin_right, speed[right]);
  delay(1000 * sec);
}

void setup(){ 
  pinMode(motor_pin_right, OUTPUT);
  pinMode(motor_pin_left, OUTPUT);
} 

void loop(){ 
  //         left   right
  //         tread  tread  seconds
  //         ----   -----  ---
  warp_factor(off,  off,   1);
  warp_factor(slow, slow,  3);
  warp_factor(off,  fast,  2);
  warp_factor(fast, off,   2);
}

syntax highlighted by Code2HTML, v. 0.93pm6