Google Feed APIを使ってJavaScriptでRSSを取得して表示する。

<script src="https://www.google.com/jsapi?key=ABQIAAAALzmN1hgTr2PC_IRwV5lbFRSyNpe6ieGxTDwC7hiaorwE3hy2EhSHZzpjusBl7KtoROnZK4WVyhHARg" type="text/javascript"></script>

<script src="https://www.google.com/jsapi?key=ABQIAAAALzmN1hgTr2PC_IRwV5lbFRSyNpe6ieGxTDwC7hiaorwE3hy2EhSHZzpjusBl7KtoROnZK4WVyhHARg" type="text/javascript"></script>
<script type="text/javascript">

google.load("feeds", "1");

function initialize() {
  var feed = new google.feeds.Feed("http://ranking.rakuten.co.jp/rss/daily/g100371st0sl0rt1du1ge9mb0pr00p1.xml");
  feed.setNumEntries(10);
  feed.load(function(result) {
    if (!result.error) {
      var container = document.getElementById("feed");
      var html = '';
      for (var i = 0; i < result.feed.entries.length; i++) {
        var entry = result.feed.entries[i];
        var image = entry.content.match(/http\:\/\/thumbnail.+?\.(?:jpg|gif|png)\?_ex=128x128/);
        html += '<p><a href="' + entry.link + '"><img src="' + image + '" alt="' + entry.title + '"/></a></p>';
        html += '<p><a href="' + entry.link + '">' + entry.title + '</a></p>';
      }
      container.innerHTML = html;
    }
  });
}
google.setOnLoadCallback(initialize);

</script>

<div id="feed" style="width:200px;"></div>