I just shot and stitched a panorama while waiting for a ride. Though the Autostitch iPhone app does a great job, I can't help but wish it would save the resulting panoramas to the photo library at full resolution.
 
The screenshot of the app displaying a section of the finished panorama is at least twice the resolution inside the app as is the version it saves. If the iPhone APIs limit the resolution at which apps can export to the photo library, perhaps autostitch could save to its own db and offer some other method of export (email, built-in webserver a la 'Brushes', flickr export?).
 
Regardless this one limitation, 'AutoStitch' is a lot of fun, and is well worth its $1.99 price.