1. A method for initiating real-time geo-game using geocast messaging according to a scalable tiered geocast protocol, the method comprising: a first wireless terminal (WT), programmed with a geo-gaming application and the scalable tiered geocast protocol, geocasting a game declaration to a destination geocast region containing potential participants; and a second WT, of the potential participants, programmed with the geo-gaming application and the scalable tiered geocast protocol, receiving the game declaration in the destination geocast region and responding by geocasting a response message indicating interest in participating in the real-time geo-game.