I ran into this question on the community and found out that there wasn't really any description how to create a footer, even if it's pretty much the same way as with a header. So For the easy part of it I created a video to quickly show how to make it. I also showing the difference of having a fixed header/footer and not which can be pretty handly and something that didn't exist for the footer at least when the portal came around in Helsinki.
For those who doesn't have the time to look at the video, you find the footer in the theme of the portal and the fixed footer/header is a visible field on the theme record. Footer it self is pretty much a standard widget and has the same fields and capability as any other widget.
//Göran
