Ah, sorry. What I meant was, use a regular resource (document) with your footer content in its content field. Then create a Template Variable named Footer, using @DOCUMENT xx (where xx is the resource ID of the one you use for your footer content) as its default value. In your template, where your footer goes, put the TV’s tags [*Footer*].
If you haven’t yet learned about TVs, you haven’t touched on half of the power and flexibility of MODx!
http://sottwell.com/how-template-variables-work.html
In almost all of my sites I’ll have a resource (unpublished) that acts as a container for other resources that I call "Tools". It will be the parent container for resources that I use for utility purposes, such as processors for AJAX requests, or pages for manager users to do editing tasks from the front-end, or anything else that will not ever be shown in a menu or be used as a part of the actual front-end site that visitors see. It’s just another one of the ways MODx can be used to make your life much easier.