EDIT **IN THE TIME SINCE THIS WAS POSTED THE OFFER HAS EXPIRED. **
Just a quick post for the time being as I have found an offer that may be of interest.
Sitepoint are currently giving away PDF copies of the “Build Your Own Ruby On Rails Web Application” written by Patrick Lenz.
To get your hands on the complimentary PDF copy of this fine book simply visit Sitepoint.com. Once you have supplied your email address you will be sent an email with a download link (you will also be forwarded to a newsletter sign up page, you do not need to sign up to make the most of this offer).
As well as getting a PDF copy of the book you will also receive a $10 money off voucher for the printed version which comes in the form of a link in the download instructions email. You can also download the code for the book by visiting the code archive. If your email address is not recognised you will be asked for a specific word within the book which you can easily find in the PDF.
Enjoy.