This is a couple of days off the pace, but you can download Microsoft's latest Internet Explorer Web Developer Toolbar (Beta 3) to assist with fiddly and tiresome HTML and CSS nitpicking.

Anyone with a serious amount of experience in HTML and CSS will have known, used and relied upon FireFox's Web Developer toolbar, one of the most valuable tools in web development.

I just downloaded and installed this on Vista. The toolbar doesn't display immediately, on Vista there's a problem that is resolved by logging on and logging off.

Download here