Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.
Blurb - Create and self-publish books, magazines & ebooks
Amazon Kindle - Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and...
CreateSpace - Publish your words, your way
LibriVox - free public domain audiobooks
IngramSpark - IngramSpark is an Online publishing services provider platform that allows you to publish or print books that are in high quality, and its global distribution service enables you to post and share around the globe.