Infecund Garb Yankee: Word replacement in NES roms
I took a ROM of one of my favorite NES games, Faxanadu, and replaced everything in the file that looked like a word with another random word containing the same number of letters. Here's a video illustrating the results (takes a few moments to get to the good stuff):
Source code for the program I made is after the cut.
Note: works better on some games than others. Obviously text-heavy games work best, but even then it'll be hit-and-miss. Most NES games didn't just store their text as strings of ASCII text sitting around in the ROM.