I am using Portable Firefox. It's on my jump drive which precludes me from dropping the url's into a folder since I am using it at work on the company's computer. They let us browse the web but won't let us install Firefox. We have to use IE. Firefox is so much more versatile and user friendly I don't understand why everyone doesn't use it.
Well just put the folder on the usb drive ... :-) I use folders for temporary bookmarks on threads and comments more and more. Doesn't clutter up the browser's bookmarks. I also find the history file not 'fine grained' enough to track back to posts I did.
These usb drives, all sorts -- flash or hard drives, are real handy gadgets. I am using them more and more. When coupled with small appliance servers, like the Linksys NSLU2 they really are handy.