LunaC - 10:17 am on Feb 3, 2013 (gmt 0)
Would this be cookie territory?
Use regular hotlinking code in .htaccess but allowing blank referrers
Once they land on the page, test if the real page is loaded on your site by a real visitor using a cookie. If the cookie is there, show images. If no referrer and no cookie, block / redirect?
I know nothing about cookies or if this is even possible, just thinking off the top of my head for possible solutions.