Chris Sells worked with Nick Muhonen from Useable Concepts and Nick created four samples exploring how an ASP.NET MVC application can access databases in the various ways you'll find in the wild:

• ADO.NET Connected (DataReaders)
• ADO.NET Disconnected (DataSets)
• LINQ to SQL
• LINQ to Entities (Entity Framework)

These samples were referenced in Scott Hanselman's blog post and Nick's in-depth article exploring the subject on http://www.msdn.com/data.