hi, you're not the only one. Reverse-engineering the 'documentation' patches seems to be the only way to go about it. I will probably post a demo patch a bit more approachable in the next day or two. I'm just reading the analog ins on a duemilanove (from analogue LFOs) but the principles should be transferrable.
Hi ashs_au, I have reached the same conclusion. I'm sure it was presented with pedagogic intent ;)
My experience is that although Maxuino is a pretty full-featured system, it's pretty difficult to take apart and repurpose. I'd highly recommend looking at some of the Serial communication examples in the Arduino distro (w/ included Max patches) and the Max serial tutorial. If you are just looking for a quick start on using the Arduino with MaxMSP, there are some other options available.
Andrew, many thanks for pointing me to sensorbox (and for writing and sharing it). It's just what I needed to get me up and running; very straightforward, and enough pointers to move onto driving Arduino outputs.