Amazon has just released a specific iPhone optimized Kindle book store. iPhone and iPod touch users can now easily browse and download more than 280,000 Kindle eBooks for the iPhone.

Ian Freed, Amazon vice president, said the consumer response to the new app is “tremendous”.

The app also utilizes Amazon’s 3G Whispersync technology, which essentially syncs bookmarks across the iPhone, iPod touch, and of course, the Kindle. So now, if you are reading a book on your iPhone, you can easily pick up later on your Kindle.

In related news, Amazon acquired iPhone eBook developer Lexcycle, the maker of the popular Stanza iPhone app. Stanza, the free application, gives people access to more than 100,000 eBook content partners. Lexcycle said the application will not change as a result of the acquisition.

Amazon has just released Kindle for the iPhone for free. The iPhone app now lets you read your books and synchronize your bookmarks with your Kindle reader. You can also transfer books from your iPhone to your Kindle. There are still many limitations with the Kindle iPhone app, for example, you can’t purchase books directly from the app, and you can’t view newspapers and documents on the app either.

It looks like this is Kindle’s response to Google opening up Google Book Search on the iPhone among other mobile platforms.