Must have tool for every web developer

I had the pleasure of accompanying Jeff Prosise, during a recent trip to the Carolinas.  The subject of much of his discussion was WPF/e and ASP.Net AJAX.  He clued me into a tool from Nikhil Kothari.  I would have to say that his Web Development Helper is a very helpful item.  One of the most useful things is to see the request/response of all http traffic coming in and out of your browser.  How many times do you wonder what is ACTUALLY being posted?  Finding the right tool can be painful sometimes.  Well, our very own Nikhil has your answer.  And that is the only featureset of the tool - it does DOM inspections and quite helpful in determing the causes of script errors.

Dont forget to check out his other tools as well.  I particurily like his javascript utilities.  Enjoy!