There are 6 previous versions of this script.
// ==UserScript==
// @name YouTube HQ Linker
// @namespace http://userscripts.org/users/23652
// @description Shows an HQ link by the description of a video
// @include http://*.youtube.com/watch?v=*
// @include http://youtube.com/watch?v=*
// ==/UserScript==
function main() {
var cat = document.getElementById("watch-panel"),
fixed_loc = location.href.replace(/(\&fmt=\d+)|(\#)/g, ''),
link6 = document.createElement("a"),
link18 = document.createElement("a"),
link22 = document.createElement("a"),
link37 = document.createElement("a"),
holderDiv = document.createElement("div");
link6.textContent = "360p Link";
link6.href = fixed_loc;
link6.setAttribute("style", "margin-right: 14px;");
link18.textContent = "480p Link";
link18.href = fixed_loc + "&fmt=18";
link18.setAttribute("style", "margin-right: 14px;");
link22.textContent = "720p Link";
link22.href = fixed_loc + "&fmt=22";
link22.setAttribute("style", "margin-right: 14px;");
link37.textContent = "1080p Link";
link37.href = fixed_loc + "&fmt=37";
holderDiv.appendChild(link6);
holderDiv.appendChild(link18);
holderDiv.appendChild(link22);
holderDiv.appendChild(link37);
cat.insertBefore(holderDiv, cat.firstChild);
}
window.addEventListener('load', main, false);