Although it is the "beta" version and is labelled an "experiment," I found that Tour Builder worked very smoothly, was self explanatory and intuitive to the point where I really find it unnecessary to explain it in any great detail here. I'll just give you a brief overview and link to a sample I made which pertains to the Geography SOL on the monuments of Latin America .
To build your own tour simply follow this link and sign in with your Google account. Of course, if you don't have a Google account you'll have to create one (remember that next year you will have a Google account through ACPS). After logging in, you might want to click on either "View a Tour" to see a sample--or perhaps you'd rather click on "gallery" and choose a sample to view from a list of Tours.
Eventually, you'll want to click on "create a tour" and start building your own. After naming your tour and naming yourself as the author you are then sent to an introduction page. There you'll want to describe what your tour will be about, perhaps you'll want to add a photo to this cover page. These tasks are so easily accomplished that there is no need for me to describe them.
The next step is to add the locations you want on your tour. You simply click on "add location" and begin to type in a name...with all of the locations on my sample tour, it automatically completed the location before I finished it. I tried my location--"Modest Town, Virginia" and it handled that just fine. In a window on the right I flew there in just seconds and viewed clear satellite images of all my neighbors' houses. You can adjust this view using controls which appear when you run your mouse over the image. When you get things adjusted to a view you like, you can lock that view in so that it is what the student sees as they take the tour--although they will be able to pause the tour and experiment with the controls. For example, by moving the little statue type figure on to the image, they can see what the "ground level" view looks like for that location. By going under "advanced options" and clicking on "show historical imagery" one can even add a slide bar allowing the viewer to see satellite images from earlier years (the earliest I found was 1931). This could be really useful in a lot of ways. For example for a science teacher who wants to teach about the changing shoreline.
It is easy to add up to 25 copyright free images (per location) from Wikipedia or other sources. It is easy to add links to articles about the location. It is easy to add videos --however, it is not so easy to add a video that actually works with our filters.
After you click on "done editing" a "share" button appears which gives you a web address which you pass on to those to whom you wish to grant access to your tour. The address is long and complicated--so it would be best to either shorten it, or post a link to a site students can just click on (I'd be happy to work with you on that). A simple URL shortener is http://goo.gl/ - simply paste the long URL into the box on this site, click "Shorten URL" and a shortened URL is automatically created. Portaportal is one good site for sharing bookmarks.
In summary, Google Tour Builder is user friendly and an extremely useful tool. I would think a geography teacher would want to make tours taking the students to the sol listed monuments on each region of the world. I;m not sure I can come up with any immediate applications for math teachers, but I can think of them for almost every other subject area. I can also see engaging students by having them build their own tours.
