Here's the iPhone Player/Stage Remote Control project! There's a .pdf that describes how to setup Xcode in the .zip file.
The goal of this project was to use the Player/Stage robotics code on the iPhone to communicate and control robots. I discuss how to setup the Xcode development environment. There are two example Xcode projects. The first one is an Objective-C project that wraps around the C++ Player/Stage code. The second project is a very primitive C++ program running on the iPhone without any UI. Both of these Xcode projects are fully documented and will serve as a starting point to iPhone Player/Stage development.
iPhone Player/Stage Remote Control Project: iPhonePlayerStage
Feel free to ask questions and let me know how you use the code.