The Photosynth website currently hosts two different types of imagery: panoramas and photosynths.
You can upload panoramas to the website in three ways, currently. Use Microsoft Research's free panorama stitcher ICE ( http://bit.ly/msrice ), use the plugin for Adobe Photoshop ( http://bit.ly/pstops ), or use the Photosynth app for iOS ( http://bit.ly/photosynthforios ). As sniziolek notes, panoramas are created from a single point of view, looking outward in many directions. The closer the subjects of your photos are, the more important it is for your camera's lens to stay the same exact place in the air. Panoramas are not photosynths.