For anyone out there who has stopped users from being able to edit SharePoint sites via FrontPage using the DisableWebDesignFeatures attribute in the Project tag of ONET.XML, be aware that users will be able to edit the site (customize/unghost) with SharePoint Designer!
So this technique will only stop users from editing your site with FronPage 2003, and will not stop users of previous versions of FrontPage, or of SharePoint Designer.
Blog fodder provided by my buddy Chris :-)