Google Base
Ran across this in XML-DEV, and Googled it. Google Base: All your base are, in fact, belong to us, tells the story very well.
This is the right model. It’s very clever.
Google is moving past tags, and into different sorts of containers. The different components of this technology are going to allow people to create ad hoc applications. We saw a lot of this after Katrina, and we’ve saw a lot of it come out of Greasemonkey hacking.
The ability to create a special page that has a few different controls that can interact with each other is enough to give any one person the ability to create a real application.