If you're new to Laravel 4 and Composer, you might be confused when you start getting errors like this:
PHP Fatal error: Class 'BlaClass' not found in project/vendor/laravel/framework/src/Illuminate/Bla/Bla.php on line xyz
This has to do with Composer's class autoloading, and is very easy to fix. Run
composer dump-auto, and then try re-running whatever you were trying to do before, which should now work.