AutoStitch iPhone (2€) is a fully automatic image stitcher for the iPhone. This application allows you to create wide-angle views and panoramas with any arrangment of photos. As David Lowe is on the team, they presumably use SIFT Keypoints. Some time ago I used their Autostich for Win32 application and I was quite impressed. Nevertheless sometimes the software produced bad stitches when there was too much overlapp. I got cleaner results, when I removed one photograph.