このようなもの:
動作中の jsFiddle の例: http://jsfiddle.net/Gajotres/cbeTD/
HTML:
<div data-role="page" id="index">
<div data-theme="b" data-role="header">
<h1>Index page</h1>
</div>
<div data-role="content">
<a href="#popupBasic" data-rel="popup" data-role="button" data-inline="true" data-transition="pop">Basic Popup</a>
<div data-role="popup" id="popupBasic" data-position-to=".footer-example">
<a href="#popupBasic" data-rel="popup" data-role="button" data-inline="true" data-transition="pop">Button</a>
</div>
</div>
<div data-theme="b" data-role="footer" data-position="fixed" class="footer-example">
<h1>Footer</h1>
</div>
</div>
CSS:
#popupBasic {
box-shadow: 0 0 0;
border-width: 0;
border-radius: 0;
background: transparent;
}