mass-mp3-retag.sh
I needed to tag some MP3 files to transfer them to my Hi-MD player (I know, I'm a technological caveman sometimes...). Since I have the most important music infos encoded in the directory structure, I could write a little shell script to automate this.
This is why a Unix-ish system beats Windows: You can combine simple tools with a simple, yet powerful programming language to automate almost everything if you want to. On Windows you probably would have to download a 3rd party program for that.