Currently, my sketch is checking an input pin every time round the main loop. If it detects a change, it calls a custom function to respond to it. Here's the code (trimmed down to the essentials):

int pinValue = LOW;

void pinChanged()
{
    //...
}

void setup()
{
    pinMode(2, INPUT);
}

void loop()
{
    // Read current input
    int newValue = digitalRead(2);

    // Has the input changed?
    if (newValue != pinValue) {
        pinValue = newValue;
        pinChanged();
    }
}

Unfortunately, this doesn't always work properly for very short changes on the input (e.g. brief pulses), especially if loop() is running a bit slowly.

Is there a way to make the Arduino detect the input change and call my function automatically?