I routinely use Google Maps to check out building-to-building wireless shots, either directly or via Ubiquiti's AirLink. I also have followed (in a low key sort of way) various 3D interactive simulations like Edushi (roughly "E-City") which covers many cities in China. There are more pointers in this blog post of a few years ago.
Now a friend, Terence Mak, is going after the vacation planning market directly with a new company "3rd Planet." They're not on the air yet, but they're working on their first project, Road to Everest, which will allow you to cover the trekking route to Everest basecamp, hopefully later this year. Meanwhile, there's an article here: http://www.huffingtonpost.com/karen-rubin/travel-planning-goes-3d-3_b_888538.html
Definitely something I want!