Nice examples of using .NET 4 dynamic keyword with Linq?

Question

So I Just got a recommendation from Amazon for LINQ to Objects Using C# 4.0: Using and Extending LINQ to Objects and Parallel LINQ (PLINQ).

It says that the book introdu

Answer 1

What I've done that gets me the result is this, but I would think there is a better way.

 using (SqlConnection connection = new SqlConnection(this.Connection.ConnectionString))
{
  connection.Open();

  SqlCommand command = new SqlCommand(query, connection);
  SqlDataReader reader = command.ExecuteReader();

  reader.Cast().AsQueryable().Dump();      
}