Compare Microsoft, Yahoo and Google Maps
Compare Microsoft, Yahoo and Google Maps on one Webpage
"Map Compare allows you to evaulate which mapping technologies is best. All three maps are locked together so panning, zooming and changing map types will effect all maps the same. You can also use the tab pane to try out various map features like; markers, popups as well. "
Best Maps - Google (Carographically)
Best Aerial/Satellite - Virtual Earth (Higher Resolution more UK coverage)
Best Geocoder - Yahoo (percentage match returned but Live Local does Geocode UK addresses)
So a Mashup of Google Maps, Virtual Earth Aerial view and Yahoo Geocoding would be the ideal solution.
Nearest found is Flash Earth where is it easy to switch layers between mapping sources.
Does not support geocoding as yet.