I have yet another AREF question:
I'm interfacing an MMA7260Q accelerometer which uses 3.3V power and has an analog interface. I'm powering it straight from the Duemilanove's 3V3 supply. Is there any reason I can't also connect the Arduino 3V3 line to AREF, so I can get the full 10bit resolution of the ADC?
Also, after reading the discussion on http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1236499795 I take it that I shouldn't put a resistor between them, and that all I need to do is call analogReference(EXTERNAL) before I call analogRead(). Right?