In Google Reader this morning, I found an entry in the Programmable Web API feed for DabbleDB. DabbleDB is a "Web 2.0" application that combines "the best of group spreadsheets, custom databases, and intranet application into a new way to manage and share your information on the web." I'm usually pretty skeptical of anything with the "Web 2.0" moniker, however, I'm very interested in new and better ways to present, manage, and integrate data. In addition to providing a very compelling interface for building "applications" through the browser, DabbleDB also provides a Plugin API that allows you to create new "derived fields" by calling out to external HTTP-accessible applications (perhaps we could call these services?).
For a good overview of the functionality offered by DabbleDB checkout this "whirlwind demo", that won Best in Show at Under the Radar: Why Web 2.0 Matters". When you're done there you can find out more on the explore page.
While I don't think I could have built it nearly as well as the DabbleDB folks have, what they've built is very similar to what I had in mind for the "ideal" platform for building out our data extensibility platform. While our core schema is locked down, we do want our customers to be able to extend our application and their data to fit their specific needs. In order to do this, I'd really like to provide our clients with a nice UI for defining the structure of their "extension data" in a way that is as intuitive as what you can see in the DabbleDB videos. Dabble's own extensibility for "derived fields" is also of interest. They're allowing derived fields to be added to sets of data by linking to external services, which is very similar to some ideas we've had. The obvious difference is that they've actually built it. 
Anyway, this all reminds me of Alex's Data 2.0 idea. I wonder how much of it will show up in the next release of Base4.NET?