GlobeGlider in action: glide and book hotel in 3D!
Globe Glider is a 'geo-browser', a tool for discovering location-related information on the Internet.
Globe Glider integrates leading map services (Google Earth, Google Maps, Microsoft Virtual Earth) with comprehensive sources of information on places, points of interest and located content.
Look at their project on Youtube about hotel booking online in 3D and Mashup!
I feel it's complicated (with this beta version), but it's maybe the futur.