The form class

class form extends form_core {

	public static $errors = array();
	public static $form_data = array();
	public static $lang_key;

	public static function open($attr = array(), $lang_key = '', $errors = array(), $form_data = array(), $hidden = NULL)
	{
		is_string($attr) AND $attr = array('action' => $attr);

		self::$errors = $errors;
		self::$lang_key = $lang_key;
		self::$form_data = $form_data;

		$action = $attr['action'];
		unset($attr['action']);

		return parent::open($action, $attr, $hidden);
	}


	public static function errors($title = 'Oops there was an error!')
	{
		if (empty(self::$errors) OR ! is_array(self::$errors))
			return '';

		$output = '<div class="form_errors"><h3>'.$title.'</h3><ul>';

		foreach(self::$errors AS $key => $error)
		{
			$error = Kohana::lang(self::$lang_key.'.'.$key.'.'.$error);
			$output .= '<li>'.html::anchor('#'.$key, $error).'</li>';
		}

		return $output.'</ul></div>';
	}

	public static function label($text = '', $data = '', $extra = '')
	{
		// Do we need to call Kohana::lang()?
		$text = (strpos($text, '.') === 0) ? Kohana::lang(self::$lang_key.$text) : $text;

		if ( ! is_string($data))
		{
			isset($data['for']) AND $field_name = $data['for'];
			// Use the name if we have one
			isset($data['name']) AND $field_name = $data['name'];
		}
		else
		{
			$field_name = $data;
		}

		// Display the errors
		if (isset($field_name) AND ! empty(self::$errors[$field_name]))
			$text = '<a name="'.$field_name.'">'.$text.'</a> - <span class="error">'.Kohana::lang(self::$lang_key.'.'.$field_name.'.'.self::$errors[$field_name]).'</span>';
		return parent::label($data, $text, $extra);
	}

	/**
	 * Creates an HTML form input tag. Defaults to a text type.
	 *
	 * @param   string|array  input name or an array of HTML attributes
	 * @param   string        input value, when using a name
	 * @param   array        array of error messages
	 * @return  string
	 */
	public static function input($data, $value = NULL)
	{
		if ( ! is_array($data))
		{
			$data = array('name' => $data);
		}

		// Set the automatic value if there is one
		$data['value'] = (isset(self::$form_data[$data['name']]) AND $value === NULL) ? self::$form_data[$data['name']] : $value;

		// Default class
		! isset($data['class']) AND $data['class'] = 'long';

		isset(self::$errors[$data['name']]) AND $data['class'] = $data['class'].' error';

		return parent::input($data, $value);
	}

	public static function password($data, $value = '')
	{
		if ( ! is_array($data))
		{
			$data = array('name' => $data);
		}
		
		$data['type'] = 'password';

		return self::input($data, $value);
	}

}

Your View

<?=form::open('admin/members/add/', 'members.add.form', $errors)?>
	<fieldset class="ujstyle">
		<div class="spacer w99">
			<div class="block left padding">
				<?=form::label('.display_name.label', 'display_name')?>
				<?=form::input('display_name', $form['display_name'])?>
			</div>
			<div class="block left padding">
				<?=form::label('.username.label', 'username')?>
				<?=form::input('username', $form['username'])?>
			</div>
			<div class="block left padding">
				<?=form::label('.email.label', 'email')?>
				<?=form::input('email', $form['email'])?>
			</div>
			<div class="block left padding">
				<?=form::label('.password.label', 'password')?>
				<?=form::password('password', '')?>
			</div>
			<div class="block left padding">
				<?=form::label('.password2.label', 'password2')?>
				<?=form::password('password2', '')?>
			</div>
		</div>
	</fieldset>
	<p class="right"><?=form::submit('submit', Kohana::lang('members.form.save'))?></p>
</form>