I would say that the search history that you get from Google is an example of automatic bookmarks. If you go to a place via a google search, Google will automatically mark it here.  These marks are well indexed and it is relatively easy to return to find them again even many months after your initial visit.  For example i visited a page about round cornered css boxes that showed one box staying in a fixed position on the screen.  I didn't booklmark the page but i studied it in detail and it ended up influencing my thinking about the web designs that i was working on.  About a month later i wanted to refer to it again but could not find it in my fastblogit bookmarks ... oh well, after some 5 minutes rooting around in my search history, there it was. 

Since it is an influential page it deserves an intentional bokmark, see [item 2716]. An intentional bookmark is far easier to find than the automatic sort. Just type in a fragment of a tag that you remember about the item in the live search box, and boom, there it is ... the 5 minutes of rooting around can usually be avoided .