Laravel 3 base model. I usually use it to extend from it.

base.php

<?php

class Base extends Eloquent {

	/**
	* @var
	*/
	public static $timestamps = true;

	/**
	* @var
	*/
	public $rules = array();

	/**
	* @var Laravel\Validator
	*/
	private $validator = null;

	/**
	* Returns validation rules
	*
	* @return array
	*/
	protected function getRules() {
		return $this->rules;
	}

	/**
	* Merge validation rule arrays
	*
	* @return void
	*/
	protected function addRules($rules) {
		array_merge($rules, $this->rules);
	}

	/**
	* Returns instance of validator
	*
	* @return Laravel\Validator
	*/
	public function getValidator() {
		if ($this->validator == null) {
			$this->validator = Validator::make($this->attributes, $this->getRules());
		}
		return $this->validator;
	}

	/**
	* Validates the model
	*
	* @return boolean
	*/
	public function valid()
	{
		return $this->getValidator()->valid();
	}

	/**
	* Validates and saves the model
	*
	* @return void
	* @throw InvalidModelException
	*/
	public function save()
	{
		if(! $this->valid()) {
			throw new InvalidModelException(get_class($this).' is not valid.');
		}
		parent::save();
	}

	/**
	* Return validation error messages
	*
	* @return array
	*/
	public function getErrorMessages()
	{
		return $this->getValidator()->errors->all();
	}

	/**
	* Returns model as string
	*
	* @return string
	*/
	public function __toString()
	{
		return $this->id;
	}
}

class InvalidModelException extends Exception {}