Speeches and presentations
Using the lens of the glasses as a miniature teleprompter over your eye could change speech and presentation making forever. The lines of your speech could scroll down the screen at a pace that you chose (or that the voice recognition software detected that you were going), and only you could see it. To the audience, you would appear to be looking straight out, even while reading from the display. Of course, the glasses themselves would give you away—but someday those glasses might become a contact lens.
Another problem with presentations is that you can't see your own slides, which are usually projected behind you on the wall while you're speaking. Sure, you could stay glued to the podium, where you could see the slides on your laptop, but most presenters want to move around freely when addressing an audience. The glasses could overlay a transparent view of your slides, along with any presentation notes you might need.
The glasses could be extremely useful—albeit in a different way—during the Q&A session after your presentation. If a tough question arises in connection with a past event or statistic, say, your support team could send you relevant information via the glasses lens. Knowing the the right thing to say is valuable at any time, but in a public affairs context, it can be priceless.
History of places
Content can become a hundred times more meaningful when presented over the real-world thing it relates to. One of my favorite sites, oldsf.org, maintains a collection of old pictures of San Francisco organized over a Google map on the basis of the part of the city visible in the photograph. You can also move a slider up and down a timeline to see photos from specific time periods.
If such content were retrofitted to display on the glasses, it might truly come alive. As you walked around the city wearing the glasses, historical pictures of specific places you were seeing through the lens could appear. You could fix your eye on the steps of City Hall, and then use the slider to go back in time to superimpose older and older pictures of the scene, watching the ghosts of the past come into view and depart again.
Social mapping and navigation
Wearable AR might make services like Google Street View go social. Today these services have to pay fleets of cars to drive around and snap millions of still photos of streets and surrounding environs. The fleets must return to the streets periodically to keep the street views up to date and accurate.
Now, imagine that Street View used imagery (even video) captured through the lenses of thousands of Google Glass users and recorded to the server. Street Views would be more accurate because many many more views would have contributed to them. User images would come from many places (such as inside malls, on beaches, or in forests) where the Google camera cars can't go.
The map makers would have to develop the technology for piecing together the best of the millions of user views of a particular place. The process would involve continually replacing older or inferior images with newer or better ones.
Nutrition and shopping
When you were at the grocery store, you'd be able fix a certain product in your lens, and then see an overlay of all the nutrition information about that product. Food companies would begin touting their ability to make this nutrition information easily accessible via the augmented reality app.
You could port the nutrition information to a dieting site (like Weightwatchers) and/or an exercise site. You'd then immediately know how much of the food you could eat while adhering to the rules of your diet, and how much exercise you'd have to do to work off one serving of the food. Knowing the nutrition, dieting, and fitness aspects of the food you were looking at would help you make better-informed decisions about what and how much to buy.