Edit in JSFiddle

var delay = 100;
$('li').each(function() {
    $(this).animate({ 'margin-top': '-80px'}, delay += 100);
});
<body>
    <nav>
        <ul id="navi">
            <li><img src="http://placehold.it/64x64" alt=""><span>Home</span></li>
            <li><img src="http://placehold.it/64x64" alt=""><span>About</span></li>
            <li><img src="http://placehold.it/64x64" alt=""><span>Search</span></li>
            <li><img src="http://placehold.it/64x64" alt=""><span>Photos</span></li>
            <li><img src="http://placehold.it/64x64" alt=""><span>Rss Feed</span></li>
            <li><img src="http://placehold.it/64x64" alt=""><span>Podcasts</span></li>
            <li><img src="http://placehold.it/64x64" alt=""><span>Contact</span></li>
        </ul>
    </nav>
</body>
* {
  margin: 0;
  padding: 0;
}
ul {
  list-style-type: none;
}
body {
  min-width: 800px;
}
#navi {
  position: fixed;
  width: 750px;
  top: 0;
  right: 10px;
}
#navi > li {
  float: left;
  width: 100px;
  height: 100px;
  text-align: center;
  margin-right: 5px;
  border: 1px solid #D6E9F5;
  border-radius: 0 0 10px 10px;
  background-color: #EEF6FB;
  padding-top: 10px;
  transition: all .5s;
}
#navi > li span {
  display: block;
  font-size: 13px;
  letter-spacing: 2px;
  color: #90C5E4;
}
#navi > li:hover {
  margin-top: 0px !important;
  background-color: #DAEBF6;
}