On the Box UK site there's a recent post where they "unbox" Silex the recent micro-framework release from Fabien Potencier and the Symfony community. They test things out by creating a sample application, a simple feedback form.

“Silex is a PHP micro-framework for PHP 5.3. It is built on the shoulders of Symfony2 and Pimple and also inspired by sinatra.” - description from the Silex website. It allows you to pick and choose what components of Symfony2 you want to use. [...] Like Ruby’s Sinatra, it provides a way to get web apps up and running with minimal effort and very little boilerplate code.

He talks about the "installation" process (downloading the phar and dropping it into a directory) and includes code snippets of the parts of his application - the basic routing, twig templates and a POST handler for the form submission.