I've already done downtown Cincinnati and around the perimeter of UC. There's so much signal in the air that I'm suprised that cooked pigeons weren't falling out of the air...
As far as I know, there isn't any software for the Palm, so you'd be better off tossing a notebook into a backpack and strolling around. You could even be playing MP3s on it with Netstumbler beeping over the top of the tunes!