I wrote a tutorial back in Dec 2007, on getting the free mediatomb application running (with Fink) on Mac OS X Leopard for streaming media to a Playstation 3 system on your home network. This tutorial gets a lot of visitors even today, and therefore I wanted to post an update which should resolve any further unanswered questions. At the time of writing, I had documented some issues encountered while getting mediatomb version 0.10.0 to install and run correctly on my OS X machine. Since then, the application has been updated and several issues have been corrected. The current version 0.11 of mediatomb installed correctly on my system with no failures (removes the big step of patching the string_converter.cc file).
I shall assume you have Fink correctly installed and running on your system. If not, there is a tutorial on the Fink website (or refer to my previous post).
Fetch a copy of mediatomb by executing the following operation in Terminal -
$ fink fetch mediatomb
Next, install.
$ fink install mediatomb
You will need to initialize the mediatomb application by running the following command (assuming you chose the default path during the Fink installation) -
$ /sw/bin/mediatomb
This should create a .mediatomb folder in your home directory, with the config.xml file included for mediatomb settings.
This config.xml file has also been updated to include helpful comments on the updates required to run mediatomb with a PS3, as follows -

Make the necessary changes, and you should be along on your path to streaming your media effortlessly to the PS3. As always, you can let me know in the comments if something did not work for you. Good luck!