The World Wide Web is like a huge country, dotted with hundreds of thousands of sites, and each site contains some information. Despite the size of this country, transportation from any site to another requires only a mouse click and under the right conditions takes just a few moments. This kind of travel - 'surfing' - can be an absorbing form of amusement and can produce many serendipitous discoveries, but such semi-random approaches to the Web usually confine users to limited areas, leaving most of the Web untouched.