I wrote a blog post here which explains how you can take Dayle Ree's model validation code and turn it into a trait.

Traits are a great way of implementing this kind of feature, rather than extending the Eloquent model!

Check it out :)

<?php  
    trait ValidationTrait {
        public $errors;

        public function validate($data) {
            $Reflection = new \ReflectionClass(__CLASS__);
            $ReflectionClass = $Reflection->newInstance();
            if(empty($ReflectionClass->rules)) return TRUE;

            $v = Validator::make($data, $ReflectionClass->rules);

            if($v->fails()) {
                $this->errors = $v->failed();
                return FALSE;
            }

            return TRUE;
        }

        public function validationErrors() {
            return $this->errors;
        }
    }