The author is mixing up two things: APIs and sensors and doing a bit of hand-waving across the join.<p>APIs are a solvable/solved problem - there should be no reason why web apps can't follow the same model for sharing contacts, accessing the camera etc.<p>Sensors? Depends which you mean. Web apps can get location data to a certain degree and can probably fall back to just asking in some scenarios.<p>What other sensors? I'm not aware of many killer social applications using my accelerometer or barometer.<p>There's a germ of an interesting idea here. More meat on it please.
>...a smartphone can work out much more. It can see who your friends are, where you spend your time, what photos you've taken, whether you're walking or running and what your credit card is.<p>Except a PC knows who your friends are (email clients, Skype, other IM), the OS and browser know "where" you spend your time, PCs have a photos directory, and your browser might know what your credit card is.