Using LocalConnection and C# .NET Windows Application
The Professional Flex 2 book comes out in May. The title of the post is part of Chapter 26: Integration with External Applications (page 626-641).
You can check out the rest of the Professional Flex 2 table of contents here.
Chapter 26 will show a working C# .Net windows application work with Flash through LocalConnection. It is more of a starting point then an in-depth C# application. But its worth taking a look at if you have ever wondered how its done.
There are other gems in the Professional Flex 2 book. The logging chapter goes over in detail the Flex 2 logging framework (Chapter 19: Debug and Test), something that is not fully utilized by most developers, at least in my opinion.