I see a lot of demos for a lot of apps. Today, in particular, I sat through a dozen back-to-back demos for startups launching at Disrupt next week. Some of them really blew me away. But none of them quite compare to the unexpected demo I got after my long day when I walked into a Palo Alto CVS to buy some toothpaste. As I was waiting in the checkout line, a very polite Stanford college student named Parth Bhakta asked me if I would be willing to test out a prototype for an augmented reality mobile app.