Actually if you use the source projects link they have a "DotNetNuke" solution which does what you describe: "DotNetNuke is an open source Web Portal Framework / Content Management System application written in ASP.NET / VS.NET-VB. It is based on the IBuySpy Portal Solution Kit with extensive modifications, including support for multiple websites from a single database/codebase installation." I'm not sure if thats the answer you're looking for though.
John McConnell
Active Modules, Inc.