Great article Aaron. I’m one of those “design in the browser” guys. Is great for prototyping, handy to make adjustments site-wide (over multiple page templates) and the eye candy can still be done in Photoshop. I also read an article where they’d use Indesign as layout-tool..
And Modernizr is awesome..

@Ralph, I used to have a piece of JS-code that would fetch the size of the window and add an element with the width/height values updated with every resize.

Nowadays I use this, the creation of a pseudo-element (in this case on my site-title element = logo top left), which tells me which mediaquery is active. (see it in action on my ‘in-redesign-redev’ stage site: http://tomhermans.simpelewebsite.be/)

/* mediaquery reporter */
.site-title:before { position: absolute; top:0; content: “320 and up”; background-color: red; color: white; font-size: 16px; padding: 5px 10px; }

.site-title:before { position: absolute; top:0; content: “480 and up”; background-color: green; color: white; font-size: 16px; padding: 5px 10px; }

.site-title:before { position: absolute; top:0; content: “768 and up”; background-color:blue; color: white; font-size: 16px; padding: 5px 10px; }

etc..
Just put any of these in the correct media-query (I start with 320, and go up..)
Delete ’em when you’re ready of course ;)