I used to use a Visor Pro then Visor Prism as my primary GPSr using a Magellan GPS Companion springboard module and GeoNiche. This worked well for me in the beginning but had limited mapping. I still use GeoNiche on a Palm TX with a bluetooth GPSr in addition to my primary GPSr (Meridian Color). Some people prefer CacheMAte but I love GeoNiche. Not only will it help point you to the cache, it will store all the data about the cache including logs if you want. It is not necessary to use it with a GPSr, but I prefer to. GeoNice comes with its own conversion tool, EasyNiche which convert gpx files to pdb file to be loaded into you Visor. By the way, I no longer use the Companion GPSr, so if you want it, it's yours. You can check out GeoNiche here: www.raydarllc.com