Dear visitor there are many way to add social bookmarking sharing gadget and you can add them easily to your site. Here i copyed a gadget code for you from www.sharedthis.com . Just copy following red code and paste it to your blogger html/javascript gadget.
<span id="st_finder"></span><script type="text/javascript" src="http://w.sharethis.com/widget/stblogger2.js"></script><script type="text/javascript">var switchTo5x=true;stBlogger2.init("http://w.sharethis.com/button/buttons.js", {"sharethis":["large","ShareThis",""],"facebook":["large","Facebook",""],"twitter":["large","Tweet",""],"reddit":["large","Reddit",""],"stumbleupon":["large","StumbleUpon",""],"digg":["large","Digg",""],"myspace":["large","MySpace",""],"delicious":["large","Delicious",""],"pinterest":["large","Pinterest",""],"linkedin":["large","LinkedIn",""],"email":["large","Email",""],"orkut":["large","Orkut",""]} , "8074fcf0-b9d4-4114-a1d5-316a626f3700");var f = document.getElementById("st_finder");var c = f.parentNode.parentNode.childNodes;for (i=0;i<c.length;i++) { try { c[i].style.display = "none"; } catch (err) {}}</script