O’Reilly Media’s Emerging Technology conference (now just called E-Tech) got into full swing this morning in San Diego. The theme of this year’s gathering is “Remix,” and the morning speakers described and demonstrated a passel of Web technologies that show how standards like XML and RSS are enabling new, often user-developed functions that marry services such as searching, photo sharing, and mapping.

The highlight of the morning was a talk by Amazon CEO Jeff Bezos. Amazon’s A9.com unit launched a search engine site last year, and has been busy updating its capabilities. One of the group’s key ideas, Bezos said, is to turn A9.com into a highly versatile “vertical search” engine, meaning that users could go to A9 to do either a general Web search or a specialized search within a specific database, such as PubMed, the largest compilation of online publications about health and medicine. “But we can’t build thousands of vertical search engines,” Bezos said. “We’d rather have a simple way of ‘consuming’ other searches and integrating them into the A9 page.”

A9’s programmers came up with a few simple extensions to the RSS protocol (for Really Simple Syndication, a system now commonly used to share or “syndicate” content across web sites) that allow owners of specialized databases to create buttons that A9 users can add to their personalized Web search page. For example, Koders, a group of open-source developers, has created a button that limits searches just to the Koder.com database of open-source code. Bezos’s A9 example was only one of the cases presented this morning of “Web services” finally coming to fruition in ways that invite participation, therefore capitalizing on the intelligence of users.

More details to come later today!