I received an email the other day from a reader (Mike) looking for an automotive GPS he could transfer geocaching info to. He asked about doing this via POIs, with a possible goal of getting all U.S. geocaches loaded. I pointed Mike towards some resources and we corresponded a bit more. He ended up buying a Garmin nuvi, and I asked him to keep me posted on his quest. I heard back from Mike today and he's given me permission to share his experience:
"The Garmin Nuvi is a USB Mass Storage Device, so I figured it might work with the Mac iBook I use and my main machine at home. To my delight, the Nuvi is automatically recognized and mounted on the desktop as a removable drive when plugged in.
I shelled out the $30 for geocaching.com premium membership which allows you to define some pretty exacting queries (they call them Pocket Queries) for downloading to a handheld device. Any Pocket Query returns up to 500 cache locations in either GPX or LOC format together with a MobiPocket file of all the cache details.
So, I ran a Pocket Query to give me up to 500 caches within 75 miles of home. Since these run overnight, the next morning my inbox had a message with a zipfile containing the cache waypoints in GPX format. I unzipped the waypoints and loaded them into the Garmin/Waypoints directory of the Nuvi.
Lo and behold, after rebooting the Nuvi, its "My Favourites" menu now lists the waypoints and they appears as little treasure chest icons as I drive along. The only issue is that the name of the cache is the waypoint GCxxxx, rather than its real name, but I think that GPSBabel might be able to solve that one. I can also load the Pocket Query files into MacSimpleGPS and send them to my eTrex. So, I've yet to solve the database of all US caches question, but at least the Nuvi is proving more exciting."
I was intrigued with the idea of building a large database of caches, so I asked Mike how big the Pocket Query file was. The answer...550 KB.