just to aid in the description, photosphere aids in the creation of extended dynamic range images.
How that works is that to create an HDR image requires one to photograph the same scene at a range of exposures. This ensures that you capture detail often blown out in the highlights, or lost in the shadows.
What makes photosphere unique (well there is no app like this on the mac, but unique in similar aps on windows) is that it includes an automated alignment feature. So should you take these multiple exposures w/o a tipod, and hey are out of registration, it does its best to align them.
Ifyou save your image as an openEXR file, I also posted another free utility here to view them...
Conventional use for these images can be for image based lighting in 3D aps like Lightwave 3D. You can also use this to take an exposure wedge of an image to later edit in photoshop.
To give you some perspective on this trchnology, here are some websites...
some hdri products....