When you are not happy with your customizations to a site, WSS and MOSS provides an option of reverting back your site to the original site definition version.
The option is called "Reset Page to Site Definition Version". This is located at Site Settings -> Reset to Site Definition. Luckily, there are two levels for resetting: a single Page, or the entire site.
Single Page obviously resets just the selected page. Confusion arises from the second option because of the inconsistent usage of the word "Site" by Microsoft. In this case they really mean "Site" as a single site(SPWeb). When this option is selected for reset, it does not reset the entire site collection. It also does not reset its sub sites (sub webs) to the original site definition. Just the selected site is reverted back to the site definition version. Neat!
