I'm developin' network game, where players would monitor game news in their client app (Iphones). There would be one server (php based service with mysql) and client with preinstaled my app.
Each user will send (may not to send) information about their location to the server (that is easy) and server will write it to the game's database.
I want to allow my users to see information (about other players) on real time. And I don't want to make a cycle with timer witch will do a request to the server. I want my clients to listen (wait) for the server command with users inf (xml or other) to come.
what tech should i use ? (I write in objective c and php and asp.net ))