Then I came up with this clever idea to have a little change script which would tickle the XML nodes of the web config file so I could just run that every time I got latest version. But it still was a pain because I had to remember to perform this action or it was more difficult to maintain.
Well, I just learned that .NET has a built in solution (that wasn't very well publicized apparently). Apparently, you can place the attribute [file="user.config"] in the web.config file and it will point to that file for application setting overrides. So you could then create that file in the application directory to hold your personal overrides for the default app settings. The file should look like this:
<add key="key" value="value" />
Note that 'appSettings' is the root node. The user.config file does not have to exist. .NET will just ignore a missing file and use the default values in web.config.
If you do create this file make sure you do not put it into the project (and, thus, source control) so as to avoid overwriting individual's settings.
I found this in the MSDN article: Team Development with Visual Studio NET and Visual SourceSafe - Chapter 4: Managing Dependencies
There are lots of other details in there that are helpful to know if you are building software in a team environment.