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.
Matt Kruse's JavaScript Toolbox presents a number of excellent best practice ideas including: using var, feature detection, when to use square bracket notation, avoiding eval, referencing forms and form elements, avoiding the with keyword, using onclick instead of JavaScript pseudo-protocol, using unary + to type convert to numbers, avoiding document.all, not using HTML comments in script blocks, avoid cluttering the global namespace, avoiding prototype.js, avoiding synch Ajax calls, using JSON and the correct way to use script tags
Christian Heilmann offers us Dishy, a JavaScript REST API for talking to del.icio.us. Taking full advantage of del.icio.us' JSON format and the script element, Dishy doesn't need a server-side proxy. Its a useful helper class for easily getting information from del.icio.us.
Stuart Langridge provides unobtrusive JavaScript that makes HTML tables sortable by their table headers. To enhance a table to be sortable requires the addition of the classname sorttable
PPK describes the three main data formats for requesting data from the server, weighing up the advantages and disadvantages. In the ensuing discussion the general feeling is that JSON is the most popular and simplest method.