I\'m currently implementing a Monotouch application that will eventually be ported to Monodroid. The application is just a client to an OData Web service. Nothing too fancy
May be a bit late, but this cross-platform mobile development video is quite helpful. I'm also writing an MT app which will be ported to Android and WP. For data storage I'm seriously considering Vici CoolStorage which is supposed to make data model completely re-usable. Additionally, I'm moving any platform-agnostic code to Utilities and Common projects inside the solution. I also hope to be able to re-use web service communication code in MD and WP. The rest is iOS specific at the moment.
It will be very interesting to know how your project is going. Is code re-usability really paying off?