i have two web services. One with user functionality, one with admin functionality.
Both services effectively work with the same object types, for instance:
Use the slsvcutil to create the WCF proxy on the clientside (assuming the clientside is a .net application), reference the DLL which contains your objects and it will be used for all endpoints that pass the same object in the DLL
Open Visual Studio Command prompt from the Start -> Visual Studio 2008 -> Tools -> Visual Command Prompt
goto directory similar to
C:\Program Files\Microsoft SDKs\Silverlight\v3.0\Tools
type slsvcutil and follow the syntax
slsvcutil http://somewcfservice:8080 /r:CommonLibrary.dll
where CommonLibrary.dll is the dll that contains the business objects
[edit] fixed the fact that the project is a silverlight project