OK, so you want to see an examle where we are managing a collection? On the same line as Person and Employee, what if we did a lab where we create an Organization class that accepts Employees. This can store the employees and provide ways to display them? We could also generate a XML hierarchy tree such as:

static void Main(string[] args)
        {
            Employee TheCeo = new Employee(new Person("The Frog", "WiBit"));
            TheCeo.SetEmployeeId(0);
            TheCeo.SetJobTitle("CEO");

            Employee e1 = new Employee(new Person("Testerson", "Test"));
            e1.SetEmployeeId(1);
            e1.SetJobTitle("Director of East Coast Sales & Marketing");
            e1.SetManager(TheCeo);

            Employee e2 = new Employee(new Person("Mill", "Bill"));
            e2.SetEmployeeId(2);
            e2.SetJobTitle("Director of West Coast Sales & Marketing");
            e2.SetManager(TheCeo);

            Employee e3 = new Employee(new Person("Face", "Harry"));
            e3.SetEmployeeId(3);
            e3.SetJobTitle("Sales Manager");
            e3.SetManager(e1);

            Employee e4 = new Employee(new Person("Fone", "Eye"));
            e4.SetEmployeeId(4);
            e4.SetJobTitle("Marketing Manager");
            e4.SetManager(e1);

            Employee e5 = new Employee(new Person("Droid", "Anne"));
            e5.SetEmployeeId(5);
            e5.SetJobTitle("Sales Manager");
            e5.SetManager(e2);


            Employee e6 = new Employee(new Person("The Fly", "Buzz"));
            e6.SetEmployeeId(6);
            e6.SetJobTitle("Marketing Manager");
            e6.SetManager(e2);

            Organization org = new Organization("WiBit.Net");

            org.Add(TheCeo);
            org.Add(e1);
            org.Add(e2);
            org.Add(e3);
            org.Add(e4);
            org.Add(e5);
            org.Add(e6);

            Console.WriteLine(org.ToXmlString());
        }

The XML output would look like:

<Organization>
	<Name>WiBit.Net</Name>
	<NumEmployees>7</NumEmployees>
	<Employees>
		<Employee>
			<EmployeeId>0</EmployeeId>
			<LastName>The Frog</LastName>
			<FirstName>WiBit</FirstName>
			<JobTitle>CEO</JobTitle>
			<Employees>
				<Employee>
					<EmployeeId>1</EmployeeId>
					<LastName>Testerson</LastName>
					<FirstName>Test</FirstName>
					<JobTitle>Director of East Coast Sales & Marketing</JobTitle>
					<Employees>
						<Employee>
							<EmployeeId>3</EmployeeId>
							<LastName>Face</LastName>
							<FirstName>Harry</FirstName>
							<JobTitle>Sales Manager</JobTitle>
							<Employees>
							</Employees>
						</Employee>
						<Employee>
							<EmployeeId>4</EmployeeId>
							<LastName>Fone</LastName>
							<FirstName>Eye</FirstName>
							<JobTitle>Marketing Manager</JobTitle>
							<Employees>
							</Employees>
						</Employee>
					</Employees>
				</Employee>
				<Employee>
					<EmployeeId>2</EmployeeId>
					<LastName>Mill</LastName>
					<FirstName>Bill</FirstName>
					<JobTitle>Director of West Coast Sales & Marketing</JobTitle>
					<Employees>
						<Employee>
							<EmployeeId>5</EmployeeId>
							<LastName>Droid</LastName>
							<FirstName>Anne</FirstName>
							<JobTitle>Sales Manager</JobTitle>
							<Employees>
							</Employees>
						</Employee>
						<Employee>
							<EmployeeId>6</EmployeeId>
							<LastName>The Fly</LastName>
							<FirstName>Buzz</FirstName>
							<JobTitle>Marketing Manager</JobTitle>
							<Employees>
							</Employees>
						</Employee>
					</Employees>
				</Employee>
			</Employees>
		</Employee>
	</Employees>
</Organization>

What do you think? Not exactly astronomy (which is a hobby of mine), but it fits in the realm of the simple examples we strive for.