melonbooks_permalink.user.js

// ==UserScript==
// @name           melonbooks permalink
// @namespace      http://fuba.moaningnerds.org/
// @description    append permalink to melonbooks book id
// @include        http://shop.melonbooks.co.jp/shop/list/*
// @require        http://gist.github.com/3238.txt
// ==/UserScript==

var ids = $X('//tr[./th[contains(text(), "商品番号")]]/td');
ids.forEach(function(item){
    var id = item.textContent;
    item.innerHTML = '<a href="http://shop.melonbooks.co.jp/shop/detail/' + id + '">' + id + '</a>'
});