To add to my previous post talking about .MonoDroid, MonoTouch and WP7 cross platform design.Found a fairly robust Rest Client that works with all three.
Some of the features of note
Automatic XML and JSON deserialization
Multi-part form/file uploads
Automatic detection of type of content returned
I've been racking my brain on how best to design a durable rest client for mobile development.
Well this may not be my silver bullet but, it looks like it could be pretty damn close.