.round{
-moz-border-radius: 6px;
-khtml-border-radius: 6px;
-webkit-border-radius: 6px;
border-radius: 6px;
behavior: url(border-radius.htc)
}

http://www.plan-zero.org

Cross browser css round corners with no images, using google's code .htc
http://code.google.com/p/curved-corner/

Cross Browser Round Corners

css, images

CSS