PPF-O-Matic is the most popular PlayStation Patch patching tool for Windows and Mac OS. However, the current Mac version costs $1.99, and older versions are PPC-only. Why pay for a free app? PPF-O-Matic v3.0 for Windows is free, so here's a solution to the paid free app: a port of PPF-O-Matic v3.0, for Mac OS X and it's OS X 10.7 Lion compatible!
Version 3.0: Release notes were unavailable when this listing was updated.
Mac OS X 10.5 or later