Amazon has announced that its Kindle application for the iPhone, iPad and iPod touch has been upgraded.

The new update enables e-books to have embedded audio and video built into them. This will no doubt be good for bringing up relevant songs that have been quoted or maybe reading an audio description. One example that's quoted is that with cookery books you can view a demo of the recipe being prepared.

One of the first books to take advantage of the new feature is Rick Steves' London which now gives an audio tour of London as you walk.

In addition to the new embedded audio/video the latest Kindle application has been optimized to take advantage of the Retina display on the iPhone 4.

You can download the Kindle application form Apple store.