At some point, in your WSS or MOSS customization and development process, you'll likely need to create a Custom Application pages. Custom application pages differ from site pages in that they are compiled and not customizable by the user. (to learn more about application pages click here).
If you'd like another good sample project to work off of, check out the CustomApplicationPages download Ted Pattison Group's download section.
I'd also like to point out that Ted covers the specifics of this download in his book Inside Microsoft Windows SharePoint Services 3.0 which you can purchase in our SharePointers store.