If your digital camera didn't come with software to allow you to combine multiple images into a panorama you may be interested in PanEdit Lite 1.09. It automates the main part of the process, leaving you with manual control at the end to fine tune the alignment and brighness. Maybe surprisingly, its a piece of Freeware from the Big Blue, IBM.

The link below is to PanoGuide.com which has a review and links to download sites NB, the IBM dowload link no longer works. The site itself has reviews of other stitching and panorama s/ware, but I'm happy with this one.

PanEdit Lite