I actually made up a design for a unified drawer design for the Camino browser, ages ago, which I thought was pretty cool at the time. Unfortunately at this time Camino was about to ditch the drawer (against my wishes). I don't browse full screen, and I think most people don't ... but I lost that argument.
This is one of my original concept drawings. The idea was to merge the HI for three things (bookmarks, history, and tabs (aka "sessions") into a single list. One part of this design which is still innovative is that the list of tabs (or "sessions") was universal to the whole app, and it didn't matter what window you looked at them in. I thought that was cool.
A later iteration took the merging a step farther. Note that this was drawn before tabbed browsing was invented!
Finally, a contribution from someone else (sorry, I have no record of who..) which clearly is a precursor to the Omniweb thumbnail tabs. I bet Omni ripped it off... They have the guts to make this kind of leap.