This may not make sense at first, but diaries seem like a good place to ramble through metaphors a bit.

For most of the early years of the Internet (as TCP/IP was arriving and the ARPANet->Internet transition was going on), the Internet and the computers on it were pretty much wide-open. Developers could build applications connecting an address and a port to an address and a port. With thousands of ports available, a limited number of people actually on the Internet, and a relatively open architecture, this model did quite well for a lot of years.

As the Web arrived and more people starting connecting to the Internet, all those open ports had to be hidden behind firewalls and private - though still TCP/IP - address spaces. Instead of wide-open access, developers created "portals" of various kinds, providing Web-based access to all kinds of information. Instead of connecting directly to the systems with the information, Web sites presented intermediate views. Access to information was now constrained by the portal.

Portals quickly grew huge, as different people in an organization used different parts. Fortunately, simple techniques like bookmarks let people find their way around without having to start from the beginning again. Some developers took advantage of the visibility of URLs to create meaningful and memorable identifier for information as well.

I see Web Services as moving to what I'll call a "porthole" model. Information is available, but through pretty small openings. Instead of the multiplicity of URIs that Web development has thrived on so far, Web Services (on the SOAP model) proposes to use far fewer URIs but let them have multiple services behind them. Less "space" is exposed to the world, but information still flows through that space. figuring out which porthole you want requires either advance knowledge or a query process (UDDI, WSDL) that itself likely (though not necessarily) goes through portholes.

It seems that the landscape for information exchange keeps shrinking. While ports remain available at the foundation, and portal models continue to dominate "traditional" Web site development, portholes are the next big thing. I'm not sure what pinholes will look like.