I just got an invite to Microsoft Live Labs Pivot and I am currently testing it out. Although, I haven't found a practical use of it, it looks visually interesting. Other than that, this desktop application seems resource intensive.
Microsoft describes Pivot as follows: "Pivot makes it easier to interact with massive amounts of data in ways that are powerful, informative, and fun." It is difficult to pinpoint what exactly that means, because its doesn't seems like a search engine. Also, it is unclear if this has anything to do with the semantic web.
Pivot uses Trident, Seadragon and .NET. (In fact, this is quite apparent once you experience the app for yourself). It feels like a desktop version of Photosynth with images of data (as collections) instead of images of places.
Here are some screenshots:
