Apple should allow iPhone 4S with Siri to communicate with each other. This would be mind blowing. For example, If I ask Siri to 'find a time John Doe and I can meet' and it will search your calendar, then cross check over the network with his calendar to calculate an open time in your schedules. This would obviously only work if both parties have Siri but that would be really cool. There are endless things this can open doors to.