I've been experimenting with the Iron web browser.  I downloaded from PortableApps.

Here's a sample of how to use it with  multiple profiles. These are all available to be used simultaneously and keep their web browsing, bookmarks, etc. all separate from one another.

Video showing use of multiple profiles(simultaneously):
https://www.box.net/shared/fb64a9bf7f1f070b34a6"

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