Google announced on the Google Maps blog that that have introduced "rooftop" geocoding for U.S. addresses. What this means is that you can get GPS coordinates at the house level, and not just a spot in the middle of the street in front of an address. Thus, you can tell if an address is on the left or right side of a street, for example.
Would be good to see this for European addresses as well. This data is certainly available - Atlas Maps can provide rooftop geocoding for addresses in Prague, and similar data must be available for other cities in Europe.