NOT WORTH THE TROUBLE TO WORK IN IE -'FAIL'
THIS jQuery plugin adds a bunch of extra divs to "fake" the rounded corners, but the deal breaker is that is finds the containers background color and makes these shapes based on that color. This means that it doesn't work on transparent background and would cause you to have to "match" the background color with the corner colors…NOT WORTH IT….ROUNDED CORNERS show up in IE9 using border-radius and all other real browsers. IE8 and previous will just have to live without the rounds…something that gracefully degrades anyway. There are other ways with HTC files and VML but again, it's not worth it. And the older browsers we are targeting must have js on for this plugin to work obviously as well. Not worth it.
http://jquery.malsup.com/corner/