http://www.panasonic.com/business/provideo/support/software.asp
Click on P2 driver. Accept and scroll all the way to the bottom. Click on the small print for Mac.
I would not recommend offloading your P2 cards directly to a hard drive. Get yourself a P2 card reader (PCD2). Use ShotPut Pro from Imagine Products to help offload your cards to your hard drive. I believe in doing the the right way. This protects you and you client if something goes wrong.
Check out this tutorial:
http://library.creativecow.net/ross_shane/tapeless-workflow_fcp-7/1
Steve Eisen
Eisen Video Productions
Vice President
Chicago Final Cut Pro Users Group