Create a extend command on Blade for Laravel 4.

setVarInBlade.php

<?php
/*
|--------------------------------------------------------------------------
| Extend blade so we can define a variable
| <code>
| @define $variable = "whatever"
| </code>
|--------------------------------------------------------------------------
*/

Blade::extend(function($value) {
        return preg_replace('/\@define(.+)/', '<?php ${1}; ?>', $value);
    });