Seadragon comes preloaded with a variety of snapshots, including some from the Library of Congress, world maps, large artwork, and user-submitted pictures from -- a program that stitches large-scale images together to create a faux 3-D composite. (At the time of this writing, Photosynth has been experiencing problems and is inactive.)
I was immediately impressed with the quality of Seadragon's images. The "city lights at night" picture comes through with stunning clarity, filling the 3.5-inch screen. When I scoped out the aerial maps section, Seadragon found my current location and gave me a sharp overhead view. I daresay the picture was crisper and more detailed than anything I've seen from Google Earth.
Seadragon uses the iPhone's multi-touch capabilities to zoom in and out, and each picture loads and focuses quickly. For large image collections, Seadragon provides a slideshow view. You can add content through other Photosynth users and RSS feeds such as and .
It's obvious on first impression that Seadragon has potential, but what's the future of this app? If it could be seamlessly paired with photojournalism sites such as I can see it changing the way we view mobile media.
Seadragon is available only on the iPhone and iPod Touch at the moment. No word yet as to when Microsoft will release the app to its own service.