Microsoft may have a competing smartphone OS, but that isn't stopping them from releasing apps for their competition. Their latest iOS app is Photosynth, an app that allows you to take 360 degree, three-dimensional panoramic photos with your iOS device. You launch the app, tap to take a starting picture, then move around to take pictures to add to the panorama, trying to line up the center dot with the dashed lines to add new photos to the panorama, adding new photos until you feel that it's complete. When you're finished, the app saves a 2D version of it to your Camera Roll. This process is invisible and automatic, though - you won't even know that it's saved there unless you check, as even App Store reviews complain that there's no way to save photos to your Camera Roll from the app, despite the automatic saving. You can also share to Bing Maps, Facebook, and Photosynth.net.
The app has a few drawbacks. Your photos need to be taken in consistent lighting conditions, or else the stitching process will make your photos look weird, as different photos might have different exposures. There is an exposure lock in the settings you might want to turn on to help this out. The app occasionally loses your position as you move around, which can create spots where a photo may be randomly mismatched with the rest of the panorama. Finally, it seems difficult to create a photo with straight edges, if not impossible, so you photos will largely be jagged-edge affairs. However, this app still lets you create some unique-looking panoramas that even a standard panoramic photo app can't match.
The irony of this situation is that Photosynth is actually not available on Microsoft's own Windows Phone 7 yet. The reason apparently has to do with the level of camera access that iOS provides to apps - apparently they can access the camera API in ways that Windows Phone 7 does not yet allow, so the app won't be on there for the near future. Photosynth is available for free, with support for 3rd generation and up iOS devices, including the iPad 2's camera, although the app does not run natively in iPad mode yet.