Z-Index without absolute position

Yes: use position:relative; z-index:10.

z-index has no effect for position:static (the default).

Note that z-index is not a global layering system, but only differentiates ordering within each positioned parent. If you have:

<style type="text/css">
  div { position:relative }
  #a  { z-index:1  }
  #a1 { z-index:99 }
  #b  { z-index:2  }
</style>
...
<div id="a"><div id="a1">SUPER TALL</div></div>
<div id="b">I WIN</div>

…then #a1 will never render above b, because #b is layered above #a. You can see a demo of this at http://jsfiddle.net/DsTeK