Does anyone use both an iPhone and an Android device and switch back and forth between them by swapping the SIM? If so, how do you deal with the iMessage activation and deactivation thing? Can you simply just turn off iMessage before swapping the SIM into the Android? I've tried this, and my wife's iPhone continues to try to iMessage me even after I've turned off iMessage on my phone. Does it usually take a while to "kick in" after turning it off?