This is one of my favorite dumb new features of the game (and something similar was in Arena, as well, I think). If you missed/ignored Rescue Requests in your playthrough, as I did for a good chunk of the game, you can request aid in dungeons from other players and receive a small fraction of HP/SP from each person who heeds your call, and you can in turn help out other players. That's pretty nifty by itself, and probably a godsend in the early dungeons, but the real reason for doing this is crafting custom messages for rescued players to see, and seeing their creations. You can only use predetermined words and symbols in a predetermined order, so expressing your message may take some creativity. As you can imagine, this is used only in an entirely serious manner, and in no way involves making oblique references to genitalia or excessive use of "WOOHOO!" (or both).
So, show off some messages, either your own or someone else's!
Here's the message I had up at the end of my game:
From what I have in my current rescue log, there are the kinda creepy:
And the kinda clever (but still kinda creepy):