Apple's Passbook is a very interesting piece of technology that involves a lot of well-known and loved tools like JSON and RESTful APIs. See how to build a sample web app that creates and distributes passes. Though the example presented isn't a full-featured product, it can serve as a nice base to build on for more serious real world uses.
Elastic Load Balancers act as a front end for one or many servers. Learn you how to use Amazon DynamoDB as a storage facility for PHP sessions.
PHP sessions management with Amazon Elastic Load Balancer and Amazon DynamoDB
In this article you’ll create a simple link-sharing application. Its user can share a URL with a title and an optional description.