Garmin custom POIs on a Mac - revisited

Take a look at http://www8.garmin.com/products/poiloader/creating_custom_poi_files.jsp#mapsource.

Look at the section describing custom POI and MapSource. You can use the same method with BaseCamp. This is yet another way to do it. The good thing about this method is that you can use BaseCamp to organize your custom POI's. The downside is that you will have to assign icons and audio files upfront, when you are creating the POI's. This could potentially be a problem when trying to change proximity or speed alert parameters for a large number of POI's.