I recently found some useful software that automatically stitches together multiple images to create panoramics. Other panoramic software requires you to manually identify which picture goes where, but Autostitch does it all automatically.
You give it all the images, and it works out what image goes where, adjusting each one so they blend together. It works suprisingly well.
As an example, I have stitched together a panoramic I made while in the Cedarberg, during Easter 2005 (click the image for a larger version).
I didn’t do any tweaking at all, this is the raw output. Pretty impressive stuff.