NewPing Library: HC-SR04, SRF05, SRF06, DYP-ME007, Parallax PING))) - v1.7

Report back: Success!!! I tried your sample sketch on IDE 23 and 1.0. I got an error with 23, it said it could not find NewPing.h. I then put the same library and sketch into 1.0 and it compiled fine. Next, I modified the sketch to print the output from the sensors and also added a delay to slow the data to a readable level.

Here is the modified sketch that I tested with my 2 sensors.

#include <NewPing.h>

NewPing sonar1(12, 13, 200); // Sensor 1: trigger pin, echo pin, maximum distance in cm
NewPing sonar2(10, 11, 200); // Sensor 2: same stuff

#define pingSpeed 100 // Ping frequency (in milliseconds), fastest we should ping is about 35ms per sensor
unsigned long pingTimer1, pingTimer2;

void setup() {
  Serial.begin(9600); 
  // Do other stuff here
  pingTimer1 = millis() + pingSpeed; // Sensor 1 fires after 100ms (pingSpeed)
  pingTimer2 = pingTimer1 + (pingSpeed / 2); // Sensor 2 fires 50ms later
}

void loop() {
  if (millis() >= pingTimer1) {
    pingTimer1 += pingSpeed; // Make sensor 1 fire again 100ms later (pingSpeed)
    int in1 = sonar1.ping_in();
    Serial.println(in1);
  }
  if (millis() >= pingTimer2) {
    pingTimer2 = pingTimer1 + (pingSpeed / 2); // Make sensor 2 fire again 50ms after sensor 1 fires
    int in2 = sonar2.ping_in();
    Serial.println(in2);
    // Both sensors pinged, process results here
  }
  delay(1000);
  // Do other stuff here, notice how there's no delays in this sketch, so you have processing cycles to do other things :)
}