I'm pretty new to the iPhone platform, so I'm wondering what the best way to switch between OpenGL rendering and a UIView might be?
Any comments much appreciated!
There's no need to switch modes at all. OpenGL ES rendering on the iPhone is done in a CAEAGLLayer Core Animation layer. This can be used as the base layer for a UIView, which means that you can combine all the UIView layout and touch handling with your 3-D rendering. This UIView can be fullscreen or placed anywhere on the display. UIViews also can be made subviews of your 3-D view, therefore they can appear above your rendering.
The OpenGL ES Application Xcode template gives you an OpenGL layer within a UIView instance and is a good place to start. For a more complex example, I can direct you to the source code for Molecules, my 3-D molecular viewer. In that application, I use a lot of the view functionality for touch detection and place an info button in the lower right as a subview. I even replace that view with another to produce a flip animation when going to the application's settings.