It talks about using your cell phone / hand held as a physical communication device in the real world.
With wireless and blue tooth communication, your cell phone could be used to communicate with businesses and individuals out there in the real world. You can bookmark locations, get more information, profiles, and sign up and communicate with others without actually talking directly to them.
You can purchase and check out at a store without the long lines!
This is definitely the answer to social media marketing campaigns and solving problems with extending and tracking your campaign as users come and go online.
You can have a sign or billboard and the user points their mobile phone at it and it bookmarks your web site and later they can visit you. Voila....you just tracked a click through from an off line medium.
Lots to flush out here, many ideas.