The other day I had to compile a program that required me to use a UFS formatted drive, as (I guess) it had files or something that differed only in having capital vs. small letters. It could not be compiled on an HFS+ formatted drive. Fortunately, I had NFS-mounted UFS drives from other UNIX systems, so this was not difficult. But what if this were not the case? Would I have to reformat my hard drive just to compile one lousy piece of software?
I then realized that one can use /Applications -> Utilities -> Disk Copy to create a temporary virtual UFS partition. You can do this as follows:
sudo chmod 777 /Volumes/Untitled
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030608025117258