Hi, Frozen White,
Photosynth's mobile panorama apps are quite limited in the resolution of each individual snapshot which makes up a panorama. This is a result of the small amount of RAM on most phones (often only 512 megabytes of RAM) and Photosynth's shooting mode, which holds all the shots captured from the beginning of the shoot until the stitching begins. Here's a little more information: http://bit.ly/psmpr
The original way to upload panoramas to Photosynth before the mobile apps was by using Microsoft Research ICE (we all just call it ICE) http://bit.ly/microsoftice or a special plugin for Adobe Photoshop for Windows http://bit.ly/pstops
Both ICE and Photoshop can use your desktop or laptop's larger amount of RAM to take full resolution photos taken with a proper camera or even your phone's default phone app and stitch a much higher resolution panorama to upload.
Both ICE + Photoshop require Photosynth's app for Windows to upload to your account.