We managed to load Engadget in the web browser of one of the display cars using the built-in 3G connection -- it took a bit of time to load but looked nice once it was done.
Usually the process involves using both a GPS and digital camera and linking the data later, but there are actually a couple of cameras on the market with built-in GPS. In any case, once your in-laws get wind of this be prepared for a new era of vacation-picture slideshows, with a step-by-step (literally) recounting of the trip.