That said, I have an, IMO important, feature request:
Mtgoxlive.com is very misleading using the default settings. While the real market depth looks more like in your screenshot, it scales both sides independently in the default view. That is very unlucky choice for the default view, because it suggests a very misleading market state, and a single graph where the scale changes in the middle is just counter intuitive. It would be best to add a dollar based single market axis and make this the default view. Why? Because this is how it is being viewed in reality anyway, and so one could see how much fiat is involved on both sides.
I've made a change related to this. It will always plot both lines on the same BTC axis but now I show a more accurate USD axis on the right. So you get a realistic market view at the same time as being able to eyeball dollar amounts.
Excellent work! Very much appreciated! I really like this solution, clean easy and intuitive.