CTwitterInterface::urlencode

protected function urlencode($mixParams)
{
	if(is_array($mixParams))
		return array_map(array($this, 'urlencode'), $mixParams);
	elseif (is_scalar($mixParams))
		return str_replace(array('+','%7E'), array(' ','~'), rawurlencode($mixParams));
	else
		return '';
}