Gpsd
From Wildsong
gpsd home: http://gpsd.berlios.de/
Current version: 2.94
The Mac port: covers version 2.38 http://gpsd.darwinports.com/
My Mac: MacBookPro running Snow Leopard.
gpsd is a service that listens to one or more gps receivers and makes the received data available over a network connection.
The reason to run it on a Mac laptop is to make the signal available to programs needing location services in a way that is flexible and device independent.
I use virtual machines, so I should be able to let a program running on any virtual machine connect to the gpsd host running on the Mac.