I am currently working on “porting” my VB.NET test application from Pocket PC to Windows Mobile Smartphone(two binaries, but one code base) and have found the following links very useful. Treat it as a “collection of resources” for now - a detailed writeup comes in the near future!

Share Source Code Across Platforms (Devices)
This article gives you a broad overview at what’s needed.

Verify Platform Support for Code in Device Projects
A single line can kill your app - this article tells you how to tell the VB compiler to make sure that no “unedible” code is compiled.

Change Platforms in Device Projects
This little writeup tells you how to switch your Visual Studio between the two “platforms”…

If you find any other useful resources, please post them here!