I'm replying to your comment because it is on the top... But there is almost a majority of users in this thread using their browsers similarly - maybe we should get together and solve this. Maybe it will be a redesign of the difference between bookmarks and tabs as sort of "temporary bookmarks." I could see unused tabs getting popped off the stack into a bookmarks category which should automatically be selected by use of some simple search-engine based heuristic. One should be able to run their bookmarks through this categorizer to build consistent and limited categories.