This document summarizes the key aspects of developing mobile applications for the iPhone using Objective-C if you are a .NET developer familiar with C#. It outlines the hardware, software, and books required, compares the Objective-C and C# languages and Xcode and Visual Studio IDEs, demonstrates sample code, and discusses both the pleasures and pains of iPhone development compared to .NET. It also notes areas still lacking on the iPhone platform like dependency injection and ORM frameworks.