This is what worked for me on MAC OS 10.6.8 with Bitcoin-Qt 0.8.1-beta. I'm combining and editing the Pygmy script and Nick ODells answer, there were a few typos.
Also note, I opened the application with right-click >> "Show Package Contents" and then edited the files with the finder, and TextWrangler. No Terminal required!
-
Create new directory in Bitcoin-Qt.app/Contents/Resources and name it data
-
Navigate up a level and then open the MacOS folder
-
In that folder, create a new file called start.sh