USB GPS accessory and software for Mac Powerbook

[Peter Johnson]

All--

As I think about my trip to Philly, it occurs to me that I'd like to be able to use my Mac (OS X) laptop as a GPS/direction finding machine. Does anyone have a recommendation for a software/hardware package that consists of a GPS "receiver" that plugs into a USB port with software that shows where I am/gives me directions on where to do?

I feel like there was discussion about this some time ago, but I can't search on GPS because it's only three letters.

Thanks for any leads/recommendations.

Peter