Suppose you have a bunch of MP3 files whose ID3 tags are written in a non-Latin script (e.g. Russian) and you want them to show up properly in all your Unicode-supporting media players and apps.
Also suppose you're on Windows.
Here's a useful recipe assuming you have Java installed:
Download id3iconv and then open a command prompt, change to the directory containing the music and perform the following command (modify it to suit your needs!):
In the following sample: