Subsidize GPS with Ad supported devices

We bought ourselves a new GPS device and I gotta say, its worth every penny. It is especially use full on road trips and vacations. The more we are getting used to GPS devices, the less we are using mapping services like Google Maps or Yahoo Maps in our pre-trip planning. While on the road, its the GPS system that drives to restaurants, gas stations or state parks which we didn't plan to visit. GPS devices are still expensive and are costing an average of $500. The prices are going down and the adoption is going up and there in lies the opportunity of providing a "Ad supported" GPS device. CNET reports that GPS is going more and more mainstream with drop in prices.

Why the sudden popularity of GPS systems? We're not just getting lost more often, said Steve Koenig, an analyst with the CEA. Rather, as GPS devices come down to the sub-$500 level, he said, "there's a whole strata of consumers who will say, 'Yeah, that's a good service.'" And, Koenig added, it's one of those services that once experienced, many wonder how they ever did without.

I would love to see an "Ad supported" GPS device which is in the Sub-$100 price range. Advertising can bring down the cost of the device and drive the customers to the business that advertise on these devices. Companies like Google, Yahoo can tie up with navteq etc which provide the "Mapping Software", to list their adsense customers prominently on the GPS device.
Right now the GPS devices don't come with any productivity software where the users can store their preferences. Users should be able to port their calendars, to-dos, preferences etc onto a GPS devices.
I could imagine a scenario where

• The GPS prompt users to buy milk, if he or she is travelling by their preferred grocery store and has a to-do item on the list
  
• Prompt them to drop that check mentioned in the To-do when driving by a bank
• Latest discounts in Macy's or others stores which they have subscribed to recieve.
  

GPS devices must provide more features and should be a "hand held PC" with GPS feature rather than plain vanilla GPS. There should be an incentive for users to connect their GPS to the PC and thus share their habits/preferences. GPS vendors need to think beyond "navigation" and they are better positioned in a lot of ways for "location based" advertising compared to Mobile Companies.