Kindle for the iPhone was released into the net during the wee morning hours. From the Home Screen, you can access the books you purchased at Amazon, but not any of the books you’ve sent to the Kindle. You can shop via the www.amazon.com/kindlestore on either a MAC or PC to buy Kindle books. You do not need a Kindle any longer to access the low price point of the Kindle books. Weirdly the Kindle Store is not specially formatted for the iPhone.
The reading interface is very rudimentary. There is no way to control the type of font, the margin spacing, the way in which the pages move forward or backward (it takes a swipe). You can’t change the background color or the font color. The size of the font is controlled by the application as well, providing five different font sizes. There is no landscape mode at this point.
The individual books will sync the last page read between your Kindle and your iPhone app. Hopefully the first iteration of the app will be quickly improved and there will be ability to access books and documents sent to the Kindle.
Note: Someone at MobileRead confirmed that if you have an Amazon account with a US address attached, you can pay with a Gift Certificate balance which enables readers to get around those geographical restrictions.