Sometimes I want to make a port on my home network (airport and OS X laptop) accessible to the world. However, using airport utility to setup the mapping and restart the router is annoying, especially when I know you can just map the port with some UDP packets.
A little searching around revealed Port Map. It’s The Coding Monkey‘s very nice and simple GUI wrapped around their real project: a Cocoa interface for automatically port mapping. It uses the open source libraries libnatpmp and miniupnp and the framework itself is MIT licensed.
I’m always excited when I see OS X developers doing some open source work. That’s a huge part of the culture of Linux that is missing from the OS X developer consciousness. That you are legally barred from writing open source applications with the iPhone SDK is one of the many reasons the iTunes App Store is a nightmare for developers (and consequently, consumers).