For one of my projects I've built a RESTful JSON API using the awesome laravel framework. This API is used by several single page applications. The most frequently used urls are
GET routes, whose content almost doesn't change over time. So caching those responses would make sense. My first approach was to cache the responses "inside" laravel and return them later with a controller. This already led to a nice performance boost from around 160ms response time before to 60ms. The main advantage was that the database wasn't hit anymore but PHP still had to handle each request.
After a bit of research I figured out a way to serve content direct from memcached using nginx without delegating the request to PHP. This seamed like a much better way, so I rewrote the caching system using memcached. I could decrease the response time even more to around 3ms per request in a local environment (this value may vary on your system).
To make this system available to everybody I created a package called laravel-cash. It is a simple to use cache layer for your own laravel application. This package requires laravel 4.1, memcached and the php memcached extension. You can get started here.