Sorry for the silence around here lately.
Unfortunately, the next chapter of OpenGL ES 2.0 I plan to release contains detailed, step-by-step instructions based on Xcode 4 (mostly written around the time of DP2) which is still under NDA. As a result, this chapter is going to take a little longer to scrub, and I haven't had much time to scrub lately.
In the meantime, I realized that I've never linked to the PowerVR Insider SDK, so I'm rectifying that. The company that makes the GPU in all iOS devices has an SDK you can download - in fact, they have several versions of it for different platforms, including iOS. Most of the code is fairly generic C++ with just enough Objective-C around them to work, but there's a metric buttload of good code there for doing all sorts of things. Definitely worth signing and downloading, because they show you how to do a lot of common tasks. It's not very beginner-friendly, granted, but still a great resource you should know about. Most of the code is general OpenGL ES and not actually specific to their hardware, though some of the texture-related tools and optimizations are designed for best performance on their hardware and in some cases use vendor-specific extensions. If you're an iOS-only dev, that's not a problem at all unless Apple changes their GPU vendor.