Open all external links in a new window/tab. Scan all the links in an HTML document, and add target="_blank" to any that go to a different domain.

gistfile1.js

$(function(){
  var hostname = window.location.hostname.replace('www.', '');
  $('a').each(function(){
    var link_host = $(this).attr('hostname').replace('www.', '');
    if(link_host !== hostname) {
      $(this).attr('target', '_blank');
    }
  });
});