The .NET Compact Framework team just released the Consumer Technology Preview (CTP) of the Power Toys for .NET Compact Framework 3.5.  These Power Toys are tools to help you build, debug and optimizie your NetCF 3.5 applications. 

My personal favorite is the NetCF ServiceModel Metadata Tool (NetCFSvcUtil.exe) which allows NetCF clients to call web services using the Compact WCF stack.

Download it and check it out!