POI triggered audio files


Hello all, I'm new to your forum but have been involved mostly in location-aware content delivered via wi-sensitive PDAs.

See http://4274design.com/mobile_intro.html

(42N 74W is our closest lat/long confluence.)

I have a house tour project in the mid-Hudson valley and I need a GPS unit that can play a Gig of audio (more is better, images would be ideal). That information would be triggered as you drive around the tour over the course of the day.

Does anyone know of such a unit, I admit I am taking a big shortcut here asking such a question.

Thanks so much in advance.