title: Best way to do curved shadows
body: <p>For something like this:</p>
  
  <p><img src="https://img.skitch.com/20111202-gjhwbw56sj3eadk3dr28r8pb8d.png" alt="box"></p>
  
  <p>What would be the most effective way to do this? Best to do an image, or is there a way to achieve this with CSS without a bunch of hacks/extra markup that I dont know about?</p>
  
  <p>Also the shadow only <strong>has</strong> to work in IE9, FF, and Chrome</p>