Everybody knows that at the heart of OS X lies a powerful UNIX/BSD installation, but actually installing UNIX software can be a bit of pain, requiring command line trickery at least, and sometimes even compiling from the source (and dealing with dependencies, etc.). Fortunately, the Fink package management system goes a long way toward making this easier by packing much of the software in a relatively easy to use format. However, Fink still requires some command line chops, so Phynchronicity takes the Fink idea to the next level. It's an OS X GUI for installing Fink packages that's as simple as navigating through the categories and hitting the install button.
Phynchronicity is $20 and a demo is available (Fink must already be installed on your system).