What is your opinion for the best GPS navigation capability? Mapopolis's (http://www.mapopolis.com/) product uses a GPS receiver to talk to a PDA over bluetooth. The PDA navigates the driver just like Hertz Never Lost or Avis Assist. The cost for the kit including the SW, GPS receiver, power cables and vent mount is $189. It does not include the PDA. My PDA is a Tungsten T3, which according to Mapopolis is compatible with their product.  
 
Would you recommend this product? Are there comparable products that you would recommend? How are solutions that do not require the PDA?