It comes with Canon cameras. I still use PSP to edit the finer points if I need to "fix" something. But this little free package includes a great utility to stitch shots together into a panoramic. It also has a nice renaming feature where you can highlight a group of thumbnails and re-name them in sequence.

http://download.cnet.com/ZoomBrowser-EX/3000-2192_4-24035.html

This image is 10 snaps, stitched together. Most of the stitches are difficult to find. There is one with a significant shift, I must have slouched for a moment. Not too bad without a tripod, though.