If you are creating an ebook for iBooks, you might find this tip from Mac OS X Hints useful:
It describes how to extract the four new Truetype fonts Apple is distributing with iBooks 1.5. That’ll allow you to see how your ebook will look. These are the fonts.
The tip is also a good description on how to get to all the resources (sounds, pictures and the like) that ship with an iPhone app. It’s surprisingly easy to get at them.
To use this tip, you’ll need to have iTunes on your Mac and have the latest version of iBooks downloaded. You don’t need to have an iPhone, iPad or iPod touch to do that. I started getting apps before I owned any of those devices. That makes iTunes a handy way to collect apps, perhaps at discounted prices, so you have them as soon as you get the device.
–Michael W. Perry, Seattle