On my wish list: Static extension methods

Ideally, I want to remove as much lambda expressions as possible out of my repository classes. Using Subsonic, I want to implement my own fluent methods which do not require any lambda in the implemented repository class at all.

Now, please correct me if I'm wrong, but while you can make a generic extension class you can't really make static extension methods in c#? Code would be something like this:

public static class GeneralExtension{
   public static T ById(this T entity, int id) where T: IActiveRecord
   {
      return T.SingleOrDefaul(x=>x.Id == id);
   }
}

And implementation would be something like this:

public class TaskRepository : IScrumblrRepository
{
   public Task Get(int id)
   {
      return Task.ById(id);
   }
}

If I find a smooth way of doing this without the use of static extension methods, I'll let you know.