I had found problems with some of the other methods mentioned here. Another way to do it would be to use layout grid B, and put your content in block b, and leave blocks a and c empty.
http://demos.jquerymobile.com/1.1.2/docs/content/content-grids.html
<div class="ui-grid-b">_x000D_
<div class="ui-block-a"></div>_x000D_
<div class="ui-block-b">Your Content Here</div>_x000D_
<div class="ui-block-c"></div>_x000D_
</div><!-- /grid-b -->
_x000D_