You may be familiar with Sau Sheong Chang's blog at blog.saush.com and if not I'd recommend checking it out (after reading this blog post of course). Sau Sheong is an expert at describing how to create common web systems with very minimal Ruby code - see his blog posts on Clone TinyURL in 40 lines of Ruby code and Write an Internet search engine with 200 lines of Ruby code for more examples of what I'm talking about.
I actually found his book Ruby on Rails Web Mashup Projects on Amazon after reading his blog and snapped it up immediately, hoping it was just as good as his blog.
Unfortunately, it's not a book of information like his web articles (I would snap that up in a minute too) - however it is a great book on how to create sites with advanced functionality by integrating other online service provider's APIs. He covers a lot of functionality in the 251 pages including geocoding addresses, mapping, SMS/Fax sending, integrating with Google Docs, PayPal payments, Amazon, Facebook and Wikipedia. Each chapter takes a new Mashup and walks through the feature set, which APIs/services will be used then a full working code example, built up in functional areas.
Packt Publishing has kindly provided me with a sample chapter for you to download and read and see the sort of information you get.
In short, definitely! The book is well written and walks you through each example clearly. I haven't needed to use many of the plugins Sau Sheong demonstrates in anger, but I've certainly had a play with most of them now and Sau Sheong's book helped me gain a great amount of confidence in having a rough understanding of each plugin before I started. The code examples are based around Rails 1.2 but in a book like this that relies on demonstrating a lot of 3rd party code rather than Rails code that isn't a problem.
While I was speaking to Packt they offered to send me a copy of Ruby on Rails Enterprise Application Development: Plan, Program, Extend. Grateful to receive new books I agreed to review a copy while doing this review I planned here. However, I can't be so complimentary about that book. It's not that it's a bad book per se, however, given that it's a book to teach Rails development (based on the old Rails 1.2 release) and that the title suggests it has an Enterprise slant - I found it lacking in Enterprise specific information and the fact that it's using 1.2 really hinders it's usefulness now. Personally I prefer Agile Web Development with Rails, which has been updated to Rails 2.x.
As I said, it's not a bad book - if you see it in a book shop and want to learn Rails, feel free to grab it - but it wouldn't be my first choice.
Packt also supplied me with a sample chapter for this book so you can make your own mind up.