Randall Munroe's (from xkcd) newest idea(kolodny.github.io)

  var snap = document.evaluate('//text()', 
    document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
    null);
  for (var i=0;i<snap.snapshotLength; i++) {
    t=snap.snapshotItem(i);
    t.textContent = replace(t.textContent);
  }