My quiz suggestion is to generate such a string in Ruby:
| yourwebsite.com |
Some kind of ascii art, with a frame where we can see a random string
in the upper border and its reverse counterpart in the bottom border.
But: the solution must be a one-liner! No temporary variables, etc.
(One can use such a string to set in mp3 or video files comment
metadata, to change its CRC, or promoting their website.)