This is pretty cool. I haven't done serious web development for almost three years now (!), but if I were still doing it, I'd want this. Download the freely available Internet Explorer Developer Toolbar, and add the following capabilities to your browser (from the site):
While I'm on the subject, I always found ProxyTrace and Fiddler to be very useful tools. They both allow you to log and inspect HTTP traffic, something that too many developers tend to ignore.