A system and method are provided to alert two mobile communications users in the event they come in close proximity to one another. The present system uses a distributed algorithm denoted as the Strips algorithm, in which a pair of moving friends with mobile telecommunications devices makes an agreement about a static buffering region between them. After the agreement is made, the users do not need to follow each other's location until one of them enters the buffering region for the first time. By doing so, they invalidate the agreement. Consequently, they replace a location update message between them, determine if they got within the vicinity of each other, and otherwise make a new agreement on a new buffering region. When one of them enters the buffering region for the first time, a message is sent to both friends alerting them of the proximity of the other.