如何设置visual studio以使用.net 3.5 CF？

I'm trying to build a Windows Mobile 5 WCF client. This project currently uses web services but I'd like to convert it to WCF. I installed the .NET CF 3.5 redistributable on the device, but how do I get the "Add Service Reference" menu option to show up on my existing project in VS 2008?I'm trying to build a Windows Mobile 5 WCF clie