Web application

Web Application Design Patterns (Interactive Technologies)
$59.95
Overall, this book is a tremendous resource for those who design for a living or find themselves responsible for a product or service and would like to understand how good design patterns used by others can make their product and service better. I found it useful as a refresher resource to catch up on elements of design that have evolved over the years to solve questions that have plagued the field. It also sparked genuine design ideas for me to generalize to questions I am charged with solving through good design. In short, it is an excellent reference that is both intellectually engaging and visually appealing. I recommend for anyone who is in our field.

Gavin Lew
Managing Director
User Centric, Inc.
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Building Scalable Web Sites: Building, Scaling, and Optimizing the Next Generation of Web Applications
$39.99
This is the first time I felt compelled to write a review for a book I bought on Amazon. I was hoping for some real interesting and hard-code technical material here. Sadly, after having wasted about $30 on this book I realized that there are many Blogs that discuss distributed caching, scaling, sharding, concurrency and all the really useful bits and you can read it for free.

Not worth it.

Programming Collective Intelligence: Building Smart Web 2.0 Applications
$39.99
It's great to have an accessible algorithms book that doesn't just cover sorting algorithms. This book shows how to implement basic algorithms for clustering, optimization, decision trees etc. For the most part the algorithms are developed from scratch, unlike e.g. in Manning's "Collective Intelligence in Action", which is more of a tutorial on using existing data mining libraries. The drawback is that while the book does a good job of teaching the basics, the algorithms and implementations may be too simplistic for use in a real project.

Python is a good language for code examples, but the code in this book is often a bit too terse (e.g. single letter variables or lists of unnamed parameters), and there are quite a few mistakes in the code.

The "collective intelligence" title and "web 2.0" connection are a bit tenuous. There are some examples where a Web API is used as a source of data, and no doubt some of the algorithms in this book can be useful in such applications. But this is clearly a book about general-purpose algorithms, and not a book about building Web 2.0 sites.

Practical Web 2.0 Applications with PHP
$44.99
This book has great examples, and great explanation of the code. I can't remember getting as much mileage out of a tech book before.
I particularly liked the intro to the Zend Framework and Prototype/Scriptaculous. I was very, very impressed.