When an iPhone application manages its own preferences, rather than using a bundle, it seems to be common practice to style that view to mimic the System Preferences app: fields are grouped by light rectangles with rounded edges; titles and explanatory text are added to the space between.
What is best used to achieve this styling? My initial thoughts are a background image to the view, but is there a better way?
You need to use a UITableView with the "group" style. I've seen some applications that "fake" it with graphics, but doing it with the correct components isn't terribly tricky. The main downside being you can't do it all in Interface Builder.
The WordPress app does this. Look at the BlogDetail controller and nib. You'll see many UITableViewCells that are returned when the table asks for the row/section data from the controller.
You can find the code at the Wordpress iPhone site.