There are three main routes to creating panoramic images:  1) Contact printing negatives and living with their original sizes 2) Physically joined panels (diptychs and triptychs or 3). Digitally merged negatives.  For a bit more on that please go here.

For the diptych option I scan 120 film 6x17cm negatives on a Nikon Coolscan 9000.  Since it only scans up to 6x9, I scan in two slightly overlapping passes and make two separate negatives and prints. 

I have recently upgraded to Photoshop CS2 with its Photomerge plug-in, but I haven't yet decided if I prefer diptychs or single panoramas for my images.  It's wonderful to live in a time when the decision is an option. (For more information about digitally stitched panoramas, please go here.)