I uploaded the first really big panorama that I took back in March 2006 to gigapan.org. It only weighs in at 0.2 gigapixels, which is small compared to some others on the site, but is still good for a jolly ol’ armchair exploring session (cheaper than another airline ticket, at least).
“Check it out”:
http://gigapan.org/viewGigapan.php?id=604 and see what you can find!
At 300dpi, a 24 inch wide panorama would require 7200 pixels across, less than 1/3 the size of the original. :)