Originally Posted By: Russ
On that note, how does it call 9-1-1? Is that a separate function?


Federal law mandates that all cellphones be capable of calling 911, with or without service, and with or without a SIM.

I'm not 100% certain, but I believe that without a SIM the iPhone will not turn on the cellular radio or attempt to find a tower, unless 911 is dialed. This is borne out by my experience with a couple of old iPhones turned over to my recombinant DNA after the SIMs were removed.