if you use Photoshop - that also has excellent automatic stitching capabilities but not many people realise it as it is tucked away as per the usual Adobe style.
I have an old version of Photoshop - V6 although I use PSP 8 mostly.
I can not find any panorama feature in either. If they have them could someone please direct me? :)
I have used Arcsoft Panorama Maker and Canon Photostitch as well as the demo version of Autostitch. I think I like the MICE one best.
the Photoshop stitch function is called Photomerge and resides in the File Menu under Automation - I cant remember which version of Photoshop it was when this was introduced.
Edit: It appeared in the first CS apparently but was previously used in Photoshop Elements.
http://research.microsoft.com/ivm/ice.html
MICE - Microsoft Image Composite Editor works on Windows XP and Windows Vista, 32-bit or 64-bit.