This is a very niche application. You have to have lost your phone, no one else with their phone is around and you have a computer around. If you are outside, y

This is a very niche application. You have to have lost your phone, no one else with their phone is around and you have a computer around. If you are outside, you probably will have an easier time borrowing someone's phone than their computer. Of course, you can visit this website with their phone instead of calling your phone. :) So the possible situation where this can be useful is when they misplace it in their house as you suggested. Skype, Google Voice (free), etc. will call the phone while providing other services. I can only imagine ad based revenue working for this, which will be miniscule even if a large customer base develops as the time spent on the site will be less than 10sec.