From Private Browsing to Sandbox Browsing

Private browsing is a great feature, but I do feel it can be quite limiting.  It concerns me greatly how many websites track what you do and share that information.  It seem everywhere I go, Facebook sits in an IFRAME showing me what friends have read the article that I am currently reading.  For a few months now, I have been splitting up my web browsing experience.  I have both Firefox and Chrome installed on my laptop.  I use Firefox to access Facebook and a few trusted websites.  I use Chrome for most other sites.  I use Chrome's Incognito mode when I price compare for things like airline tickets (I have heard they jack up the price if they detect that you are shopping around).  This pseudo-sandboxing allows me to keep Facebook away from all the sites that track using Facebook.  I use Firefox to implement the sandbox because Chrome only supports two modes, remember everything and forget everything.  What I really want is two different "remember everything" zones that don't know about each other.  Websites rendered in Chrome cannot see the Firefox Facebook cookie.

What I want is the ability to sandbox websites so that I choose which sites see which cookies.  This is similar to Incognito mode, except the browser doesn't forget everything that happened.  I would keep Facebook in its own sandbox, since a lot of sites like to integrate with it.  I don't like how I go on a site and an Amazon appears displaying something I was pricing out on Amazon, so I would keep Amazon in its own sandbox.  I would keep all my Google accounts in one sandbox.  This level of sandboxing would allow users to control which sites got to see which cookies.  Advertisers would still be able to track some of your activity, but your private information can be secured.

I haven't figured out how to manage the user interface for this feature.  How do you know which sandbox the tab you currently in belongs to?  Do you put a customizable icon somewhere?  Do you use border colors?  How do you choose which sandbox to use when you open a new tab?  Would it be better to assign a website to a specific sandbox?

This is something that Chrome might be able to support with relative ease.  Since Firefox still doesn't support having a private browsing session while having a regular session open, I don't think Firefox can easily support this feature.  With this feature, you give users a tool to enhance security and prevent tracking without turning tracking completely off.  Users can create as many sandboxes or zones as they want.