GPS Navigation for Mac laptops

I'm doing the shopping now for our first FW and I'm trying to find a GPS navigation system that will run on a Mac laptop. All the products I've found so far are for PC laptops. Does anyone have any leads for me and, better yet, some experience with one of these systems?
GPS Navigation for Mac laptops

At this time I do not believe there are any. see they have a link for all mac users to sign up for gps products.

I use a Garmin Street pilot and love it. The new model Street pilot III, has voice, which I do not have. However it has several features that are a improvement over mine. Maybe a used laptop and just use it for the gps.