Turns Powder Toy Forum's "Conversations" page into a tiny Freenode webchat box. Sorry if it's quite crappy - the script is a hundred years old!

webchat.user.js

// ==UserScript==
// @name        Powder Toy site Webchat
// @description Replaces Powder Toy site "Conversations" with webchat window. Turn off by turning off the script.
// @namespace   boxmein.net
// @include     http://powdertoy.co.uk/*
// @version     1.0
// ==/UserScript==

/* Webchat.js
 * Turns powdertoy.co.uk's Conversations window into a qwebirc IRC box for #powder and #powder-social
 * on Freenode.
 * Turn off by turning off the script :(
 * Public domain.
 */
 
var enabled = true; // Show / hide the webchat
var checkboxEnable = true; // Show / hide the small notification box
var frame = "<iframe src=\"http://webchat.freenode.net?channels=powder,powder-social&uio=d4\" width=\"568\" height=\"400\" style=\"border: none\"></iframe>";
var showCredit =  true ? " by <a href=\"boxmein.web44.net\">boxmein</a>" : ""; // Do you want credits?
var element = document.createElement("div");

var init = function() {
    if(checkboxEnable && document.getElementById("webChatBox") == null) {
        createCheckBox();
    }
    if(enabled && window.location.href.match(/Conversations\.html/) != null) {
        updateWindow(true);
  }
};
var updateWindow = function(toWhat) {
  if(toWhat) {
    document.getElementById("isEnabled").innerHTML = "Changing to frame!";
    document.getElementsByClassName("Subpage")[0].innerHTML = "Webchat frame" + showCredit + "<br />" + frame;
    document.getElementById("isEnabled").innerHTML = "Ready.";
  }
  else if(!toWhat) {
    location.reload(true); // If you don't want, then refresh.
  }
}
var removeCheckBox = function() {
  document.removeChild(element);
}

var createCheckBox = function() {
  
  element.setAttribute("style", "float: right; position: fixed; background-color: rgba(0,0,0,0.5); font-family: \"Georgia\", serif; color: white; padding: 1px; border: 1px solid rgba(0,0,0,0.9)");
  element.setAttribute("id", "webChatBox");
  element.setAttribute("align", "center");
  element.innerHTML = "<p>Conversations->Webchat is enabled.(<span id=\"isEnabled\">Enabled</span>)</p>";
  
  document.body.appendChild(element);
};
init();