It’s been some time since I looked at OpenStreetMap, but it’s got really good:
Link to GU14 7JP in OpenStreetMap
Compare this to the plain map data in Google Maps (yes, I know gmaps has streetview, but it’s really only a matter of time before that could be replicated if OSM or someone else wants it).
I have to testify it is so … I have spent now two weeks in (sometimes a bit rural) Italy and in my experience mapping data and routing were actually a bit better than GMaps (yes, they have Street View, not that important in countryside, and better UI, but OSM And was good enough). Google’s routing made me sometimes wonder (going through the parking lot and back, or running us through some unbelievable cart tracks). Just an anecdotal story, but it was suprising to me how OSM is good.
Sadly there’s lots of other things GMaps has that OSM doesn’t. I love the idea of OSM but it’s not a practical replacement for all sorts of uses yet. My personal one is transit routing: the main thing I use Google Maps for is getting around. There only seem to be very embryonic efforts at transit routing using OSM in a very few cities, so far. GMaps is also still way way ahead in POI.
I am an active contributor to OSM, one of the many thousands. In my home city of Seattle, our contributors are usually ahead of all the other mapping companies when there is road changes. The Alaska Way Viaduct is a good example. OSM was well ahead of the other map companies when the road was rerouted for tunnel construction.
OSM is fun and everyone can contribute. You don’t even have to be a programmer to make major contributions.
All the transit routing data for Google Maps is available on the web:
http://www.gtfs-data-exchange.com/