Found this article and had to share. It struck me as a great experiment, yet somehow I had never even considered this idea before.

An artist wanted to see just how dedicated the letter sorting people were in the Royal Mail in England the UK. So, she mailed letters addressed using puzzles instead of the usual name-and-address format. Of the 130 letters she mailed, only 10 never arrived. Really good delivery rate, imho, especially considering at least one of them required the postal workers to complete the crossword!!

For the full story, and other examples, click here.