Automatically Generate Buddy Classes From Model In C#

I use Linq to Sql (although this is equally applicable in Entity Framework) for my models, and I'm finding myself creating buddy classes for my models all the time. I find this time consuming and repetitive. Is there an easy way to automatically generate these buddy classes based on the models? Perhaps a visual studio macro?

[MetadataType(typeof(PersonMetadata))]
public partial class Person
{
}
public class PersonMetadata
{
public object Id { get; set; }