Xml config transformations are an easy way to provide consistent changes to web.config files when deploying applications to different environments. However, until SlowCheetah came out this useful transformation was limited to actual deploys. SlowCheetah provides the ability to complete transformations when Run/Debugging in Visual Studio on any file and could come in quite handy. Between SlowCheetah and T4 templates, maybe someone can come up with a way to have Visual Studio just code the whole app for you!