Person magnus = new Person { Name = "Hedlund, Magnus" };
                Person terry = new Person { Name = "Adams, Terry" };
                Person charlotte = new Person { Name = "Weiss, Charlotte" };

                Pet barley = new Pet { Name = "Barley", Owner = terry };
                Pet boots = new Pet { Name = "Boots", Owner = terry };
                Pet whiskers = new Pet { Name = "Whiskers", Owner = charlotte };
                Pet daisy = new Pet { Name = "Daisy", Owner = magnus };

                List<Person> people = new List<Person> { magnus, terry, charlotte };
                List<Pet> pets = new List<Pet> { barley, boots, whiskers, daisy };
                
                // Create a list of Person-Pet pairs where 
                // each element is an anonymous type that contains a
                // Pet's name and the name of the Person that owns the Pet.
                var query =
                    people.Join(pets,
                                person => person,
                                pet => pet.Owner,
                                (person, pet) =>
                                    new { OwnerName = person.Name, Pet = pet.Name }).ToList();

                Parallel.ForEach(query, x => Console.WriteLine("{0} {1}", x.Pet, x.OwnerName));
                Console.ReadKey();