ebetancourt

javascript:(function(){
  var w=window,
      d=document,
      pageSelectedTxt=w.getSelection?w.getSelection():(d.getSelection)?d.getSelection():(d.selection?d.selection.createRange().text:0),
      pageTitle=d.title,
      pageUri=w.location.href,
      tmplt="";
  tmplt="["+pageTitle+"]("+pageUri+")\n\n";
  if(pageSelectedTxt!="") {
    pageSelectedTxt=">%20"+pageSelectedTxt;

ebetancourt

wrap any function in 

javascript: (function () {
  // javascript goes here
})();

minify and then create a bookmark with the URL as the minified JavaScript

// grayscale all images without an alt tag
const css = document.createElement("style");