C# – Auto-generate DBML from entities

Is there a way to generate the DBML file from entity classes instead from database tables? This would be very useful for prototyping, where one just creates a logical model and lets the auto-generated tool create the DBML file. With DBML file, one can use SqlMetal to generate Linq to SQL classes and be done with it. So, to prototype rapidly, one would:

1.Define models

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    // etc
}

2.Run the tool (with chosen entities)

3.Get the auto-generated DBML file

4.Run the SqlMetal tool or Damiens t4 scripts to create Linq to SQL classes

5.Code against auto-generated data-context and auto-generated database (using DataContext.CreateDatabase() to create the intial DB, for instance). Some sort of DB migration would be even nicer.

Or am I weird for wanting to generate DB from objects instead of objects from DB? 🙂