- The Kindle 2 supports three types of documents: Kindle, Text and Unprotected Mobipocket. Kindle files have the .AZW and .AZW1 extensions, Amazon's proprietary Kindle document format. Text files are standard, portable documents, assuming the .TXT file extension. Unprotected Mobipocket documents are those without Digital Rights Management protection, and assume the .MOBI and .PRC file extensions. DRM documents purchased from a Mobipocket retailer cannot be viewed on Kindle.
- The Kindle 2 supports an MP3 player that can play music in the background while you read your book. You can transfer MP3 files via USB between your computer and Kindle. In addition, the Kindle 2 has a Read-to-Me application that reads English newspapers, magazines, blogs and books out loud to you. This is a useful feature to take advantage of when you are commuting by car. The audible file formats assume the .AA and .AAX extensions.
- Kindle's Personal Document Service via Whispernet lets you email approved files to your Kindle's email address. With this service, Amazon can convert these files into the Kindle document format and transfers them to your Kindle for a fee. Approved file formats are Microsoft Word's .DOC and .DOCX; Structured HTML (.HTML, .HTM); RTF, JPEG, GIF, PNG and BMP images, and Adobe PDF. The document service also accepts compressed ZIP files, which it then extracts and converts to the Kindle format.