dialog.js

// Creating a new dialog plugin
var dialog = new $.Widget("<div class='dialog'></div>");
dialog.insertInto = "body";

dialog.listen({
  open: function() {
    if(dialog.state == "closed") {
      dialog.show(); // Triggers another event
      dialog.state = "open";
    }
  },
  close: function() {
    if(dialog.state == "open") {
      dialog.hide(); // Triggers another event
      dialog.state = "closed";
    }
  }
});

// DOM Stuff
dialog.listen("default", {
  show: function() {
    dialog.el.show();
  },
  hide: function() {
    dialog.el.hide();
  },
  initialize: function(dialog, contents) {
    dialog.origin = dialog.el.parent();
    dialog.append(contents).appendTo(dialog.insertInto);
  }  
})

/* Setup -- The specific setup is separated out from the implementation
   so making special version of the dialog is simple (see below) */
var openButton = dialog.newType("open", "a.dialog");

openButton.live("click", function() {
  dialog.open();
  return false; // Should block bubbling
});

$("body").live("click", function() {
  if(dialog.state == "open") dialog.close();
});

// Usage
$.get("someUrl", function(html) {
  dialog.initialize(html);
});

/* OVERRIDE */

var openClicker = dialog.newType("open", "div.dialog");
openClicker.live("click", function() {
  dialog.open();
  return false;
});