Well this is fascinating - head over to Google Maps and ask for some directions. Set it to "walking" mode, then in Point A just put "The Shire" (no quotes) and in Point B put "Mordor."
Fascinating.
Ha! XD
I can't get it to work. It gives me actual directions. :P
I believe it's the caution message above the directions.
Yeah it'll still try to generate directions for some actual places but there'll be a little highlighted warning above the directions themselves. That's the cool part.
There's also this in the walking directions from China to Japan:
Jet ski across the Pacific Ocean
If you reverse the Shire/Mordor directions (which for some reason happened to me?) the directions warn you that it may be missing sidewalks. I know it's not actually a joke, but I still thought it was funny.... :P