Using Google Docs Viewer you can read eBooks (PDF Files), PowerPoint presentations in online. It also supports TIFF files. No need of login at your Google account. But it only supports the hosted files in online. You have enter PDF file URL to view in Google Docs Viewer.
Go to docs.google.com/viewer and enter your PDF file URL. Then click “Generate Link” Button. It will give one Link to read your file. Click it and it will show the contents of the eBook.