Happy Accidents

Have you ever messed around while hacking and accidentally produced something interesting?

For instance, I was playing aroung with the loop that that blanks out spell costs in battle, and by NOP-ing the hex, something unexpected happened.

All of the disparate spells of each character's spell lists appeared on all of the characters' menus. It was like Gogo's Magic Menu, except every character shared each other's spells...but could still learn them normally after the battle.

Obviously, this was a bugged version (unavailable spells were still blank and unselectable, but had a 255MP cost), but it made me wonder what if someone were able to get this behavior to work in a non-bugged way. This would definitely change the game. And if there were a way to make this behavior compatible with some of the more famous patches (say Imbued Magic and/or Restrict Espers) this could be used to allow for more flexibilty and it would work well with the whole themes of coming together.

But I'm a dreamer and not a coder, and I still have my own goals to work towards.  In the interest of discussion, what "happy accidents" have you discovered as you tinkered?