Rob Allen, in his Zend Framework 2 development, has come up with a list of suggestions about the use of modules in your applications, mainly relating to the structure of the files inside of them.
I've been working on a Zend Framework 2 module within a larger project that doesn't have that many PHP class files. Specifically, it has a controller, a mapper, an entity, a service and a form. As a result, the traditional Zend Framework 2 directory structure for the Account module looks [overly complicated]. That's a lot of directories for not many files! As a result, I decided to flatten it to [something simpler].
He includes both the "before" and "after" directory structures and continues on with two more suggestions - the removal of the top level "Account" folder inside of "src/" and, finally, removing "src/" all together with a slight modification to the autoloading. With a simpler module, though, something like this might make it easier to maintain and "follow" later down the road.