I go on about 3-4 cruises a year and tour the U.S. in my motor home and need routable maps for the areas I travel in. I am tired of having to input the coords for a Cache into my nuvi and then drive there, that is if I am in the coverage of my nuvi, otherwise it's dead reckoning.. I also do not wish to pay $100. for every state and country I visit. Any Help?
I guess it depends on where you are visiting. Garmin now offers the "CityXplorer" maps which you can download for $10. If you are just visiting a few cities then these will give you full routing and search capabilities: http://www.garmin.com/garmin/cms/cache/offonce/us/maps/cityxplorer
As we have discussed here before, the free routable OSM maps have some routing oddities (sending the wrong way down one-way streets, telling you to turn off the highway where there isn't any exit). But aside from that, they don't have any address search capability. So you can click on a point and they will generate a route, but you can't search for addresses and route to them.
Maybe they don't do address search, but they do route to geographic points (POI). On mkgmap compiled trail maps, I've been able to route from one trailhead to another, through multiple intersections.
While I've never tried to use an OSM map in the UK, I think it would be reasonable to assume it could get you from Tottenham Court Road, London to St. Paul's Cathedral or the Tower of London.
I suspect that routing oddities are worse in the US than elsewhere, because of the Tiger Import, which was never meant to be routable. This means that instead of just drawing it right the first time, OSM editors need to ferret out all the misalignments and add oneways etc.