corner-ribbon

Original: http://jsfiddle.net/chriscoyier/H6rQ6/1/

HTML

<div class="ribbon-content">NEWS</div>

CSS

.ribbon-content {
  font-weight: bold;
  font-size: 15px;
  color: #333;
  text-align: center;
  text-shadow: rgba(255,255,255,0.5) 0px 1px 0px;
  -webkit-transform: rotate(45deg);
     -moz-transform: rotate(45deg);
      -ms-transform: rotate(45deg);
       -o-transform: rotate(45deg);
          transform: rotate(45deg);
  position: relative;
  padding: 7px 0;
  left: -5px;
  top: 15px;
  width: 120px;
  background-color: #BFDC7A;
  background-image: -webkit-gradient(linear, left top, left bottom, from(#BFDC7A), to(#8EBF45)); 
  background-image: -webkit-linear-gradient(top, #BFDC7A, #8EBF45); 
  background-image:    -moz-linear-gradient(top, #BFDC7A, #8EBF45); 
  background-image:     -ms-linear-gradient(top, #BFDC7A, #8EBF45); 
  background-image:      -o-linear-gradient(top, #BFDC7A, #8EBF45); 
  background-image:         linear-gradient(to bottom, #BFDC7A, #8EBF45); 

  /* for oldIE */  
  zoom: 1;
  filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#bfdc7a', endColorstr='#8ebf45');    
  color: #6a6340;    
  box-shadow:         0px 0px 3px rgba(0,0,0,0.3);
}

.ribbon-content:before, .ribbon-content:after {
  content: "";
  border-top:   3px solid #6e8900;   
  border-left:  3px solid transparent;
  border-right: 3px solid transparent;
  position:absolute;
  bottom: -3px;
}

.ribbon-content:before {
  left: 0;
}
.ribbon-content:after {
  right: 0;
}