Andy Hume whittles away the various JavaScript libraries to produce a clear explanation of event delegation and how it works. Its a technique that reduces the number of event listeners attached to the document by attaching just one event listener to a container element. He presents a simple code example and talks about the benefits of event delegation, including performance and code maintenance. (Includes workarounds for IE and a Safari bug)
Tim Huegdon uses JavaScript to fix Safari's bug where clicking on a label doesn't set focus to the corresponding field element (a useful accessibility aid). Using YUI and event delegation Tim walks us through the development of this piece of code involving attaching an event listener, getting the target of an event, then finding the field that corresponds to the label, and focusing on it if its a text field, or activating / selecting the form element if its a radio button or checkbox.
A cross-browser bookmarklet to examine the box-model of any DOM element on a page. Runs on Internet Explorer, Safari (and Webkit based browsers), Mozilla (including Firefox and Camino).
A DHTML shell that allows you to query the current browser window. Includes command line JavaScript execution, mouseover DOM query, CSS input, tab completion, profiler and object inspection. Can be configured to run off a bookmarklet, and works in IE, Firefox, Safari and Opera
Using console.log outside of Firefox? Here's Joe Hewitt's simple JavaScript file to allow console.log to work on Internet Explorer, Opera and Safari. Reference the script in the page you want to debug, and add a class of debug into the HTML element, and you have a JavaScript console. There's also a command line - just like the real Firebug.
Webkit have released Web Inspector, which is a Firebug-type tool for Webkit and Safari. Contains Firebug related features like categorising resources, JavaScript console, HTTP network monitor, load time and resource size monitors, inline JavaScript and HTML error reporting.