Hi,
I just thought I would post an update to let you know that I have decided to expand this project into one that is capable of reading inputs from multiple utlity meters, i.e. Gas, Water and Electricity. I will be looking to include support for pulse optical pulse output and 'reflective' meters (that is, meters where a photoreflector is required to read an analog value), and I will be making this available as a library.
More details on my blog (link above).
If anyone else has done any work in this arena, I'd be very interested to hear from you or perhaps even collaborate.
Thanks
Richard.