Outstanding panoramas! Mine doesn't belong in the same league as those above but here's the giant Meteor Crater in Arizona. It's a mile wide and you're standing on the edge so other than multi-shot panoramas, don't know of anything but a fisheye that could get it all in.
That was taken with my old 2mp Olympus C-2100UZ, before I got my Nikon.
Regards,
Dick:)