Let\'s say you have a typical web app and with a file configuration.whatever. Every developer working on the project will have one version for their dev boxes, there will be
Configuration is code, and you should version it. We base our configuration files on usernames; in both UNIX/Mac and Windows you can access the user's login name, and as long as these are unique to the project, you are fine. You can even override this in the environment, but you should version control everything.
This also allows you to examine others' configurations, which can help diagnose build and platform issues.