When mass-renaming video files for Mai-HiME (which I recommend to anime fans out there, unless anything involving magical girls in any way is not your thing; but not the point), I made a mistake in the mv command, which caused all files to be moved to a single destination. I quickly pressed Ctrl-C, but the first four files were lost.
I immediately Googled up an instruction on undeleting files on reiserfs, which (to my dismay) involved unmounting the partition and running reiserfsck --rebuild-tree -S as root. My first thought was: “What a fool I was to choose reiserfs! Surely ext3 can handle undeletion much more gracefully!”