A protocol for wireless data exchange may be used in conjunction with two or more portable computer systems. One of the portable computer systems may be a personal digital assistant (PDA) having an internal or an external wireless communication unit. The protocol can be used by a sending application residing on the portable computer system to transparently send a wireless message to a receiving computer system. The packet is then automatically routed to the proper destination application residing on the receiver utilizing a data type identifier. The data type identifier is used by the receiver, in conjunction with an application registry, to determine the proper destination application.