There was the Digital Image Suite and several other tools like Hugin and Cool360 which I used over the last years to create panoramic images. Now there's a new tool available in 32 and 64 bit (for really really huge images!) from Microsoft Research. It's free at this point and if you're on Windows it's definitely worth the try.

"Microsoft Image Composite Editor is an advanced panoramic image stitcher. You shoot a set of overlapping photographs of a scene from a single location, and Image Composite Editor creates a high-resolution panorama incorporating all your images at full resolution. Then save your stitched panorama in a wide variety of formats, from common formats like JPEG and TIFF to multi-resolution tiled formats like HD View and Silverlight Deep Zoom."

Source: http://research.microsoft.com/ivm/ice.html