I love when Microsoft releases samples of complete applications that works with the latest technologies: they are really an important way to understand the architectural concepts and an unvaluable guide for developers.
The latest release is the Windows Mobile Line of Business Solution Accelerator, a Smart Client built using .NET and SQL Server Compact edition that shows an interesting use of .NET Compact Framework, LINQ, Dynamic SQL, Web Services, WCF, Sync Framework.
Absolutely to check...