I tried using the code as provided below when I submitted a slashdot story:
<!-- Start Slashdot It link --> <a href="javascript:location.href='http://slashdot.org/bookmark.pl?url='+encodeURIComponent(location.href)+'&title='+encodeURIComponent(document.title)"> <img src="http://images.slashdot.org/favicon.gif" alt="Slashdot" border="0" height="16" width="16"></a> <a href="javascript:location.href='http://slashdot.org/bookmark.pl?url='+encodeURIComponent(location.href)+'&title='+encodeURIComponent(document.title)">Slashdot It! <!-- End Slashdot It link -->
That's missing an end </a> tag so it made my whole site start linking.