There is alway something new to discover. Usually when you want to edit a page in SharePoint you just hit “Website actions” “edit page”. But certain pages don’t offer to edit themself, such as the edit-form for list-items. So what?
Just append “toolpaneview=2” to the address of the currently visible page; and magically you’ll see the WebPart-Editor-Pane, which allows to edit the current page. This way you can literally edit every page in SharePoint.