I am thinking about how an application can be written to work on both Windows 7 Phone and IPhone, one option is MonoTouch.Dialog for most of the UI on the IPhone and then create a layer that will let the some code work on WP7.
Has anyone looked at doing this?
There was an post about this recently on Monologue:
http://conceptdev.blogspot.com/2010/09/monotouch-meet-windowsphone7.html
You've got the right idea with regards to creating the custom UI's for each OS which access the same data.
However, Monotouch.Dialog is specific to iPhone (as the name, Monotouch suggests). There may be a similar port to WM7 which allows for easy creation of WM7 UI elements but I doubt it would be a fork from Monotouch.Dialog because it is specific to iPhone.
I haven't seen a port to WP7 of MonoTouch.Dialog yet. But it could definitely be done.
MonoTouch Dialog is really two different things that work together: the first creates the structure of the data (either from reflection or creating elements manually) and the second actually displays that structure in a table.
Both parts are kind of mixed in the same code today, so separating those two would be the first step, so that the first part doesn't depend on MonoTouch.* at all. The second step would be to port the second part of the code to WP7.
That would be a really cool project, actually. It would be very useful.