Google took advantage of its 3D acceleration tricks Wednesday to introduce Google Maps 3D photo tours. The technique uses the optional MapsGL mode, which uses WebGL to get a speed boost, to steer viewers through a 3D photo scene. The technology stitches together publicly available Panoramio and Picasa photos, using Google's own 3D depth calculations and transitions to get the added dimensions.
As it's relying on crowd-sourced photos, the scenes should become more accurate over time as more photos join the pool.
Over 15,000 well-known locations have 3D photo tours, including both US locations like Yosemite as well as international areas such as the Sagrada Familia in Barcelona or the Sydney Opera House. More locations are likely to follow over time.