I have code that references a web service, and I'd like the address of that web service to be dynamic (read from a database, config file, etc.) so that it is easily changed. One major use of this will be to deploy to multiple environments where machine names and IP addresses are different. The web service signature will be the same across all deployments, just located elsewhere.
Maybe I've just been spoiled by the Visual Studio "Add Web Reference" wizard - seems like this should be something relatively easy, though.
When you generate a web reference and click on the web reference in the Solution Explorer. In the properties pane you should see something like this:
Changing the value to dynamic will put an entry in your app.config.
Here is the CodePlex article that has more information.