Amazon has released an update to its Kindle app for the iPhone, iPod touch and iPad adding the ability to open and import supported e-book formats. Kindle 2.5 now allows users to open e-book files from sites such as Project Gutenberg and the Internet Archive directly from the Safari browser or Mail app using the “Open in” feature in iOS 4. Supported ebook formats can also be transferred to a user’s device via USB using the File Sharing…