I reworked the code in this old classic of mine.
It now fully supports auto-opening binaries (by opening a .dmg, .iso, .bin, .ppf file and clicking the appropriate select button, it will then auto-link in through the Finder).
The PPF-O-Maker can also link .txt files (for the file id.diz part).
I also fixed some bugs in this release.
I also changed the code so it should be possible to compile it on 10.3 (and less).
It also works perfectly for Lion.
The binaries are under build/Release (for Lion).
I'll recompile for Snow Leopard (and older) soon.
Enjoy...
EDIT: New release (4.2.1)
- Fixed some bugs related to importing image/PPF files.
- Optimized code for running fast.
- Changed some deprecated code (checks for Mac OS X version, chooses optimal for any version of OS X).
- Added .img support for Finder imports.
- Changed default compiler to LLVM GCC 4.2
- Fixed the code for compiling for 10.3
- Built the code for 10.3-10.7 (from Panther to Lion)
The main zip contains the build for Lion and the sources.
The other zip contains the builds for Snow Leopard, Leopard, Tiger and Panther

EDIT2: Project page.
I started a Sourceforge project for PPF-O-Suite
http://www.sf.net/p/ppfosuite

EDIT3: Update (4.3.0)
- Fixed Finder imports for Panther
- Added PPF V1+V2 support for PPF-O-Maker (smaller files than V3 but only 32bit file handling)
It's available from the project page...

EDIT4: Another new release (4.3.2).
- Added PPF V4 file format (uses dynamic offset and patch sizes, supports large patch blocks).
NOTE: Not enabled to generate by default. Select PPF Version menu item and then Version 4 to generate V4 files.
This also decreases the file size a lot while supporting fast operations.
This also means it optimally aligns the patch entry and offset entry (from 1B to 8B entry).
Also patch replacement code now supports more then 255B patch blocks.
Tests shown this to generate patches of 245,8MB (V4) instead of 279,1MB (V3) - Tested with binary test files.
- Fixed PPC code (Tested on PowerBook G4 under Leopard 10.5.8).
- Added support for PPF V4 on PPC (converting the patch size bytes and offsets to big endian - directly).

EDIT5: Yet another new release (4.4.0)
-Added full NSDocument support (multiple windows are now possible)
-Added separate NSWindowController (for better window handling)
-Added Lion full screen support
-Improved auto-opening support (detects opened file)
-Dock menu added with options to open / save among other things
-Resizing support of the window implemented
-Lion sandboxing implemented (not perfect yet, crashes on document open from Finder), use the no sandboxing version..
-Code signed on Lion + Snow Leopard + Leopard versions
-With PPF-O-Matic the 2 open buttons have been replaced with 1 open button
-With PPF-O-Maker the 3 select buttons have been replaced by 1 open button
-Help files fixed for all versions of OS X
-Updated help with latest instructions
-Certificate included (in case it is needed)
-Window shows opened PPF files after program name (e.g. PPF-O-Matic - test.ppf)
-Added new about window (nicer, cleaner)
Code is available through git or downloading from project page.
Binaries are available from the project page.

EDIT6: Version 4.4.2
This update has some more changes including:
- Better support for older Mac OS X versions.
- Several fixes
- Some optimizations
- Redesigning of the interface
- Signed now with my own developer certificate from Apple
- Made everything tamper proof
- Sandboxing works well so processes of the apps are fully isolated
- PPF-O-Matic and PPF-O-Maker will soon be available as separate apps from the Apple App Store

EDIT7: Version 4.4.2 update
- Changed code for compiling with cocotron (Windows XP -> 7 support)

EDIT8: Rebuild of V4.4.2.
- Added multiple thread support (can now really run everything together).
- For now built for 10.6/10.7 (Snow Leopard or Lion).
- Changed icon because app store rejected icon.
- Fixed window bug.
- Changed Finder app display name (just PPF-O-Matic/PPF-O-Maker now).
- Some locks for when app is running patching / making patch.
- Added PPF file version confirm dialog.
- Fixed some more bugs.

EDIT9: Fix of threads of V4.4.2 Windows
- Threading fixed for Windows.
- New alert dialogs for Windows.

Available from the project page.
http://www.sf.net/projects/ppfosuite

A little example of how the auto-linking (when opening .ppf, or image files) works.

Download small video:
https://rapidshare.com/files/2572675...PF-O-Matic.zip

New release (4.2.1)
- Fixed some bugs related to importing image/PPF files.
- Optimized code for running fast.
- Changed some deprecated code (checks for Mac OS X version, chooses optimal for any version of OS X).
- Added .img support for Finder imports.
- Changed default compiler to LLVM GCC 4.2

I would like some feedback from people who use the app.
Also requests for features (new ones) are welcome.

A Sourceforge project page has been created.
See the first post

Added support for the new PPF V4 file format (designed it myself, dynamic variable offset and patch sizes).
Fixed PPC code, tested on a PowerBook G4 (Leopard 10.5.8).

Added a new release that supports every modern feature there is in OS X.
It also is document based so it can work with multiple windows.
This means you can apply many patches at the same time (in parallel).
In Lion it even supports full screen and it has a dock menu.
And much, much more...
Enjoy...

V4.4.2 is now available and soon will be even available from the App Store.
It's probably the last version in a while (unless somebody has some good suggestions I might do).
Enjoy the (for now) final release

I added a Windows port (surely works on XP -> 7, 2000 maybe).
It's based on Cocotron and compiled with Xcode 4.1 (my own custom Cocotron SDK).
It works rather well and supports everything the Mac version supports.
Available from the project page...
Some pics below:

Update: Rebuild of V4.4.2.
- Added multiple thread support (can now really run everything together).
- For now built for 10.6/10.7 (Snow Leopard or Lion).
- Changed icon because app store rejected icon.
- Fixed window bug.
- Changed Finder app display name (just PPF-O-Matic/PPF-O-Maker now).
- Some locks for when app is running patching / making patch.
- Added PPF file version confirm dialog.
- Fixed some more bugs.

Available from the project page.
http://www.sf.net/projects/ppfosuite