"A" wish a picture of, for example, -Empire state building-
"B" deliver a picture of -Empire stat building-
Now it's "B:s" turn to wish...and so on.

It could be almost anything...maybe not porn or something like that :P
AND NO PICS OF JT-FOLKS!
So, someone could start posting a picture of....hmm...eh .. what the hell

-Empire state building-