Garmin Nuvi

Have a look at the OSM-Wiki¹. Right at the top you can read how to use OSM-maps with your Garmin device. If you want to navigate with the new map be sure to use a routable one.

Don't forget to have a look at ² to enable detailed logging on your nuvi if you haven't done this already.

hth malenki

¹ http://wiki.openstreetmap.org/wiki/OSM%5FMap%5FOn%5FGarmin/Download
² http://wiki.openstreetmap.org/wiki/Garmin/N%FCvi%5Fseries#Garmin%5FN.C3.BCvi%5FTrack%5FHack

If you don't want to go with (or can't find) a suitable download you can create your own maps from OSM using "mkgmap".

It (and "splitter", which you'll probably also need) is available from here: http://www.mkgmap.org.uk/

And an example of the process to go through to update maps is described here: http://help.openstreetmap.org/questions/1809/how-to-install-mkgmap?page=1#2440 it's the same on a Garmin eTrex and and a Garmin Nuvi.

One other thing worth mentioning - with OSM maps installed you can turn them on or off from the Nuvi menus, so you can go back to using the Garmin-supplied maps easily.

Ken Rasheed, especially fokus on the last section in the SomeonElse's answer. It is clever to have a navigation specialized data as a backup. Namely, (vehickle) navigation (depending on the automation level) requires considerable amount of specialized information and many of those are not yet in OSM. Besides, there are too many errors on line-work geometry (roads, streets...), not to mention area objects. For example, in the road data of Europe, there are hundreds and hundreds of ordinary or connecting road sections tagged as roundabouts, roundabouts tagged as ordinary road sections (or not tagged as roundabouts), wrong roundabout geometry (impossible to go around, in circle), wrong connections to roundabouts (visually connected but no noode in connection) and so on.