Proximity Text Messaging

Communities as groups of people in physical proximity have waned as communities of like minded people linked by technology have risen. But could one link the two?

Proximity text Messaging sends a text with your identifier out to your neighbors, cotravelers or other people in a defined tight area around you. Let the other people in your apartment know they are giving away Snapple outside. Tell the people on your train that you found a lost computer. Tell everyone at the party that cops are on the way. Coordinate your protest - or your escape.

I could envision some rabid users of such a service might get sick of the messages from one or more users near their residence or work. This user could be blocked, as with any caller.