The first public release of Rails Rescue Handbook, version 0.8, is for sale on Lulu for $9.95. As the version number indicates, I don’t consider this the final release of the book. But there’s plenty of good content there already, and purchasers will be entitled to upgrades for the life of the book: simply buy a copy and register it here for access to future downloads.
Rails Rescue Handbook covers everything from how to get what your client really wants to getting your app to perform faster and is essential reading, even if you're not in the process of rescuing an application