I have been running through the examples (and am having LOTS of fun!) but when I got to AnalogReadSerial http://arduino.cc/en/Tutorial/AnalogReadSerial where you read from a potentiometer, I ran into an error:
In function 'void loop()':
error: 'A0' was not declared in this scope
looking at the code:
int sensorValue = analogRead(A0);
After looking at the analogRead reference: http://arduino.cc/en/Reference/AnalogRead, only the pin is needed, not the 'A'.
It seems that if you would like to use an analog pin as a GPIO pin, using the digital functions then you need to reference it as A0 http://arduino.cc/en/Tutorial/AnalogInputPins. However the analogRead function doesn't require (or like) like the 'A'
I'm not sure if this is because I'm running an older version of arduino (0018) on Ubuntu 10.04 or if it's actually wrong on the site. Just wondering really.