The following guide assumes that you use macports to install the requirements. You can also do this the hard way by finding/compiling the stuff yourself, but if you're capable of doing so you won't need this guide anyway.
See http://code.google.com/p/pingus/wiki/MacOS_X_Compiling if you are adventurous or do not want to us macports.
This guide was written on OS X 10.5 "Leopard", where XCode brings gcc-4.0. Since that's too old gcc-4.4 is installed using macports and also referenced in the Makefile.macosx. If you have a recent compiler, just skip these parts and adapt the makefile.
First get and install macports from http://www.macports.org/ Next use macports to install pingus' requirements by typing:
sudo port install libsdl libsdl_image libsdl_mixer boost scons
sudo port install gcc44
Once all libraries are in place, you can compile Pingus with just:
make -f Makefile.macosx
Once the compilation is successful you can run Pingus directly from the top level directory of the source tree via:
./pingus
For details about the command line options etc. see INSTALL.unix
To make pingus feel at home on OS X you may want to create an application bundle. The follwogin steps will create a Pingus.app that can be used and distributed like any other Mac OS X application.
First we need some little helper utilities
sudo port install dylibbundler makeicns
Now the application bundle can be build
make -f Makefile.macosx bundle
To create a compressed package for distribution frun the following command:
make -f Makefile.macosx package