Amazon has updated its Kindle app for the iPhone, iPod touch and iPad and added in a few really nice features like real page numbering, percentage read, and Google and Wikipedia lookup.
Kindle now provides real page numbers to books from the Kindle Store. This basically means that Kindle books will mirror the print versions page numbers. This may not sound like a big deal but if you are reading in a group or in class it is very important . Also you can now see how far you have read as a percentage whilst reading the book and the app home screen now shows your progress in a list view.