One of the most important innovations of the Web 2.0 era has been the mashup. As I've noted before, mashups really need underlying meshes, and geographical ones are an obvious type. But the amazing Wikisky shows that in many ways heavenly mashups are even better than earthly ones:
The main purpose of WIKISKY is to consolidate astronomical, astrophysical and other information about different space objects and astrophysical facts.
We hope to achieve this purpose using the principle of visualization. When a person reads an article about a star, the star is only the abstraction for that reader. The person cannot emotionally feel the reality of the star without actually seeing it. We strive to create an extremely detailed sky map to help everybody to better understand the information gathering about any space object and various phenomena connected with those space objects.
Aside from the joy of being able to zoom around and into the sky just as you would over Google Earth, and the awe-inspiring sight of thousands - millions - of major structures there (the Sloan Digital Sky Survey is simply gob-smacking), where Wikisky really comes into its own is in its annotation.
As you mouse-over objects, a pop-up gives you basic information. Clicking on that object takes you to a page with links to detailed images and - most importantly - to relevant papers. This is one reason why the heavenly mashup is superior to mundane ones: there is already a huge quantity of relevant, neatly-packaged information available for the objects on the mesh in the form of published scientific papers.
The only problem is that not all of this information is freely available (though often the preprint versions are): some of the papers requires subscriptions or one-off payments. This shows, once more, why open access to research papers is vital if we are to get the full benefit of such amazing sites as Wikisky: without it, mashups are frankly messed-up. (Via Open (finds, minds, conversations).)