A typical interaction with a webmapped browser might go as follows: When the user fires up the browser, the user sees an overview of a virtual city, as if seen from high in the sky. The city is a high-level view of all the user's data. The user mouses over to one particular neighborhood and that neighborhood fills the screen. A number of buildings are now visible with labeled awnings hanging off them saying what they represent. All the currently visible buildings will be in a certain general district (say the Novels Neighborhood, Drama Neighborhood, History Neighborhood, Literary Criticism Neighborhood, and so on).
To aid the user's memory, buildings in each neighborhood should look distinctively different, as should all the rooms in a building, and so on. (Once the user has visited a neighborhood a few times, the labelings should vanish). Much of memory is of the following form: the thing searched for is near to the watercooler or it's in the bright red building next to the two-story Victorian dormer. This is easy to do by building in a large template of different ornaments and incidental detail and having them randomly assigned to each building when it's created. (Incidentally, there's a whole new job category waiting here--people who design harmonious and memorable incidental architecture.) To those who balk at the computational cost of rendering ``unecessary'' visual detail, think of this: when was the last time you visited a bookstore whose every book had exactly the same dimensions and color and so on with only their texts to distinguish them?
Selecting, say, the Novels Neighborhood building puts the user into that neighborhood. From now on, all the user can see is sites related to novels; to get to nearby Neighborhoods the user must first go back to the roof. The Novels Neighborhood building may be further divided into an arbitrarily large number of floors, the floors into an arbitrary number of rooms, the rooms into bookcases, and so on. Each selection successively restricts the user's view of the totality of data--protecting the user from information overexposure is what good information management is all about.
The advantage of such a system is that when you find that Jane Austen novel you were originally looking for, you can look over to your left to find other novelists similar to Jane Austen. Further, once the user browses the generic neighborhoods a while that user will start linking things that seem related to that usuer. The mapping system might also extract some of this linkage information simply by analyzing the user's link-following behavior; it need not bother the user to enter explicit directives. This information could then be used to reconfigure the neighborhood linkage map as seen by that particular user.