This Google Maps mashup allows the user to browse for golf courses anywhere in the US. Anyone can add a golf course if it is missing from the directory or correct the information of an existing listing.
Public golf courses are shown on the map with green map markers and private courses are shown with red markers. Each marker contains a link that takes you to the entry for that course in the directory.
From the same map developer as 18HolesFinder comes this trail finder Google Maps mashup. As with the golf course directory anyone can add a trail or edit the details of an existing listing in the directory.
The difficulty of trails are indicated by the colour of the map marker on the map. Red markers indicate strenuous trails, yellow markers show intermediate trails and green markers show that the trail is fairly easy.