A sticky footer and a sticky background in one. Take the height of your background image as your footer height and determine how much of the picture needs to be overlapped by your content. To let the sticky footer "disappear" use the same number in the main margin-bottom as you have for the footer height. This is a moderated design from original design of sticky footer from: http://www.webcreationz.nl/de-ultieme-sticky-footer-code (sorry site is in Dutch).
I just figured this out. I hope it will help someone.
HTML:
<div id="container">
<div id="main">text of your website</div>
<div id="spacer"></div>
</div>
<div id="footer"></div>
CSS:
html, body {
height: 100%;
}
#container {
width: auto; /* with number center with margin: 0 auto;*/
min-height: 100%;
height: auto !important;
height: 100%;
margin-bottom: -175px; /* height footer */
}
#main {
height: auto;
width: 618px;
float: right;
margin-top: 10px;
padding: 20px;
background-color: #FFF;
border: 1px solid #E1E4EC;
margin-bottom: -100px; /* overlap of 100 px into footer */
}
#spacer {
display: block !important;
height: 175px; /* height footer */
}
#footer {
clear: both;
height: 175px; /* height footer */
width: auto; /* with number center with margin: 0 auto;*/
background-image: url("images/plaatje jpg"; /* background picture */
background-repeat: no-repeat;
background-position: center bottom;
}