Another solution which worked for me was to clean the system font caches.
I used Linotype FontExplorer to do that. You can also use Yasu.
So summary of the discussion: If you have ps -> pdf conversion hanging up
1. Run pstopdf from the command line and see if it hangs up checking fonts...
I have exactly the same problem, and have had the problem through many versions of OS X. I do not have any .pfb fonts in my /Library/Fonts or ~/Library/Fonts folders.
I tried running pstopdf from the command line; it checks fonts and list the fonts as it checks. It hangs up on a certain tex...