If all of the images you are linking to are jpgs, in the same folder and you are using Apache, you could put the following code in a .htaccess file in that images folder.
Quote:
ForceType application/octet-stream
via sitepoint.com
i’ve been searching for this for a while now.
for some reason posterous doesn’t show the whole code to put in htaccess file.
ForceType application/octet-stream
here it is.