The Garmin nuvi 260 GPS shows up as 2 FAT drives (internal flash and SD) when connected with a standard USB-miniUSB cable.
Find crap put places by people, http://www.geocaching.com/. That site has its own dumb format (LOC files), any the nuvi (and most other Garmin devices) want the GPX format. The site will emit GPX files if you give them money, but I'd rather just convert the two formats with this loc2gpx script.