I found the answer to my question.
[data-role=page] {
min-height: 100%;
position: relative;
}
[data-role=content] {
margin-bottom: 80px; /* based on how tall your footer is and how much gap you want */
}
[data-role=footer] {
position: absolute;
bottom: 0;
width: 100%;
height: 60px /* this can be configurable, or omitted, as long as the above padding-bottom is at least as much as the height of the footer is */
padding-bottom:60px;
}
I did a variation of the answer I found by Nick here: Jquery Mobile Sticky Footer
What I changed was to use margin instead of padding so that the content didn't increase in size when there was no need for it to.