Finished silver challenge of chapter 21: add a toolbar in the web view that has a back, forward button and a button that enables / disables the buttons on the toolbar. The toolbar was created programmatically by adding the uibarbuttonitems manually when the web view controller was initialised and then letting the uinavigationcontroller handle the rest.
Didn't push through with trying to add a UIToolbar from a xib - from research, it seems that Apple wants you to load whole views from xibs only. So, it's either make the whole view (with toolbar) in a xib, or programmatically.