public static class XmlTools
{
  public static IEnumerable<string> ToXmlString<T>(this IEnumerable<T> inputs)
  {
     return inputs.Select(pArg => pArg.ToXmlString());
  }
}

new XElement("people", myPeople.ToXElements());

public static class XmlTools
{
    public static XElement ToXElement<T>(this T input)
    {
        return XElement.Parse(input.ToXmlString());
    }
    public static IEnumerable<XElement> ToXElements<T>(this IEnumerable<T> input)
    {
        foreach (var item in input)
            yield return input.ToXElement();
    }
    public static IEnumerable<string> ToXmlString<T>(this IEnumerable<T> input)
    {
        foreach (var item in input)
            yield return item.ToXmlString();
    }
    public static string ToXmlString<T>(this T input)
    {
        using (var writer = new StringWriter())
        {
            input.ToXml(writer);
            return writer.ToString();
        }
    }
    public static void ToXml<T>(this T objectToSerialize, Stream stream)
    {
        new XmlSerializer(typeof(T)).Serialize(stream, objectToSerialize);
    }

    public static void ToXml<T>(this T objectToSerialize, StringWriter writer)
    {
        new XmlSerializer(typeof(T)).Serialize(writer, objectToSerialize);
    }
}

public static IEnumerable<string> XmlSerializeAll<T>(this IEnumerable<T> input)
{
    foreach (T item in input)
    {
        yield return item.ToXmlString();
    }
}

var myArray = myEnumerable.XmlSerializeAll().ToArray();