I have it installed via fink and it works great. I use it to convert PostScript files to PDF when the system included with OSX fails (most of the time :-( )
Where did you get the ghostscript installer? was it a dmg file?
I downloaded a tar.gz file from ftp://mirror.cs.wisc.edu/pub/mirrors/ghost/gnu/current/
unpacked it, performed a ./configure and make...but what after that?
Also, does the ghostscript file that you downloaded also support file format conversion?