Looking to get a better feel for that Yosemite National Park expedition this summer? Google Maps is looking to go beyond the regular ol' snapshot and offer an experience that feels more like an actual visit -- only you won't have to leave your sofa. The folks in Mountain View have added photo tours to over 15,000 sites around the globe from Italy to the aforementioned Half Dome in California. A search for your virtual destination of choice will indicate whether or not a tour is available for that particular locale. How does it work? The outfit uses user-contributed Picasa and Panaromio photos -- only those listed as public -- alongside some fancy computer techniques to provide a 3D tour. Along the way, Maps selects the best possible path through the highest quality images. At the bottom of each photo, contributor credit is given and Goog says when more shots get shared, these tours will improve over time. You'll need Google Maps with WebGL to get the sightseeing started, though. If you're looking for a quick preview, hit the video just past the break.