I’ve pushed a number of changes to my BuildKit project on Github that bring it up to date with the latest iOS 4.0 SDK and prepares it to work with Xcode 4.0. BuildKit for iOS  is a collection of configurations, scripts and Xcode project templates to manage creating, building and using multiple static libraries for iOS applications. I based it upon a similar structure I created for Mac applications and frameworks in 2005 and 2006 after Xcode 2.1 introduced configuration files. Both leverage the multi-layered build settings in Xcode.