This is a topic I have not seen a lot of discussion on so perhaps it could fall under a “did you know” category.
In Microsoft Office SharePoint Server 2007, you can specify preferred templates, and page layouts. Basically what this means is you can tell your site to allow only specific site templates, and page layouts, when creating new sub-sites, or pages.
This is a great way to enforce consistent workspaces in an otherwise free-for-all situation.
You can configure the site templates, and page layouts to use by visiting: Site Actions -> Site Settings -> View all Site Settings -> Page Layouts and Site Templates.
The rest is very intuitive. Good Luck!