I have an idea for the bookmarks, people may have multi role in the real world, like, I'm a software engineer, so i gathered many bookmarks about software, technique. I'm also a car fans, so i gathered all kinds bookmarks about car. I'm also a investor, so i notice all the industry information that i interested. So, I have many many bookmarks, many of them have nothing to do with each other, also,there is not enough space on the bookmark bar, so i think i can change my role , and then according bookmarks appear on the bookmark bar.
So, for me, i can create 3 mode : engineer mode, car fans mode, investor mode.