Edit in JSFiddle

<div class="pic">
    <img src="http://www.muratoner.net/images/test.jpg" width="200px" height="200px" />
</div>

.pic{
    float:left;
    height: 200px;
    width: 200px;
    margin: 20px;
    overflow: hidden;
    border-radius: 10px;
    -webkit-box-shadow: 0 0 10px rgba(0,0,0,.3);
    box-shadow: 0 0 10px rgba(0,0,0,.3);
    -webkit-transition:all 1s ease;
    -moz-transition:all 1s ease;
    -o-transition:all 1s ease;
    -ms-transition:all 1s ease;
    transition:all 1s ease;
}

.pic:hover{
    border-radius:100%;
}