Programatically Creating SharePoint Web Application

http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spwebapplicationbuilder_members(office.12).aspx

http://stsadm.blogspot.com/2007/10/create-web-application.html

http://consultingblogs.emc.com/kalpeshprajapati/archive/2007/09/03/Programmatically-creating-Web-Application_2C00_-Site-Collection-and-Web-in-MOSS-2007.aspx

http://blogs.msdn.com/b/sridhara/archive/2007/04/21/add-subsites-and-provide-navigation-functionality-in-moss-2007-a-code-approach.aspx