Hatena Graph Previewer http://help-me-hackers.com/tasks/133

hatena_graph_previewer.user.js

// ==UserScript==
// @name           Hatena Graph Previewer
// @namespace      http://twitter.com/m_satyr
// @include        http://graph.hatena.ne.jp/*/edit*
// ==/UserScript==
//
// Released under the MIT license
// modified by http://twitter.com/toby_net
// see also 
//   http://help-me-hackers.com/tasks/133

var gedit = document.getElementById('graphedit');
var table = gedit.querySelector('table');
var graph = gedit.appendChild(new Image);
var titles = document.getElementById('titlecel');
var iscell = /^t[hd]$/i;

graph.id = 'graph';
graph.style.cssText = "display: none; position: absolute; padding:16px;"
  + "opacity: 0.90; background-color: #F4F4FF; -moz-border-radius: 6px;";

table.addEventListener('mouseover', preview, false);
table.addEventListener('mouseout', hidePreview, false);
table.addEventListener('change', preview, false);
var ev = {target: table.querySelector('th:nth-child(2)')};
//preview(ev);
hidePreview(ev);

function preview(ev){
  var lm = ev.target;
  for(;; lm = lm.parentNode){
    if(lm == table) return;
    if(iscell.test(lm.nodeName)) break;
  }
  var sibs = lm.parentNode.children, idx = index(sibs, lm);
  if(idx < 1 || sibs.length - 2 < idx) return;
  setTimeout(function(name){
    graph.style.display = "";
    graph.style.left = ev.clientX + document.body.scrollLeft + 16 + 'px';
    graph.style.top = ev.clientY + document.body.scrollTop + 0 + 'px';;
    graph.title = graph.alt = name;
    graph.src = (/^\/[^/]+/(location.pathname) +'/graph?graphname='+
                 encodeURIComponent(name) + '&mode=detail' +'&'+ +new Date);
  }, 9, titles.children[idx].textContent.trim());
}

function hidePreview(ev) {
  graph.style.display = "none";
}

function index(lmns, lmn){
  for(let i = -1, it; it = lmns[++i];) if(it == lmn) return i;
  return -1;
}

元のタスクがMITライセンスでってことなのでMITライセンスって書いといた(問題ないよね
詳細 http://help-me-hackers.com/tasks/133

問題ないよね

無論です。最初のバージョンに書き忘れててすみません。