i recently did my university project in GPS & backpaking in mauritius & am residing inland, in mauritius.
actually, if u buy the garmin 20x series(210-205) nuvi, it has maps built in, and works very well in here. Except that some part near the sea in soufleur i didnt receive any geo locations.
i was planning to have a website, with a little dbase of gps sight seeing points around, but that happened to be costly for me, maybe later with free asp webhosting sites, it would be easier..
If u have any help, any request, and need, i'd be pleased to respond to, here's ma email add: firstname.lastname@example.org