I have a Garmin 60 which I use on my boat and the Nuvi255W for the car. I have maps on both - and I can view these maps on my laptop with the Garmin software provided. My question is it at all possible to 'cross-use' the maps. In other words use my South African map on the Garmin 60 - bought in South Africa on the Garmin Nuvi255 which I bought in the UK for use there. I am going back to SA for a week or too and it would be great if I could upload the SA map to my Nuvi.
If you purchace the Garmin Topo maps they will work on a lot of the street GPS's as well as the handhelds like the 60's and the Colorados, Dakotas and the Oregons. Some of the street GPS's will not accept Garmin Topo's but a good portion do. These maps do noit have any unlock codes and come with their own software. You can also import these maps into Mapsource.
Over the past 10 years I have owned many Garmins and as long as they are mapping enabled devices the same map data works across all units (subject to obtainin the license key). The only problem you may have is that older units may not support the newer NT maps.