Check this out. I found some new software that kicks butt. You can take photos that you didn't intend on being panos and use this program to splice them together and you'd never know. They can even be of differing sizes. Obviously there are limits to what it can do, but so far I haven't found anything better.
. Then scroll down to the bottom of the page and then click on Download.
After downloading the program, unzip it and then run the autostitch.exe. Then click on file/Open. Choose which pics you want to stitch together and then choose open. You will have to hold down the Ctrl key to select all of your pics. This works waaaaaay better than Photoshop, although you will have to use Photoshop to crop the photo once you are finished. It will name every pano you make "pano" so you will need to change the name each time or it will copy over your last pano. Here is an example of what I did with 3 photos taken from the South Rim on August 11, 2007. And no, there is nothing wrong with my camera, that is smog from Mexico fouling up the air. The entire Sierra Quemadas from the South Rim.