I have an immediate resistance to using electronic "devices" out in the bush for all the reasons mentioned already, namely I'm going out there to get unplugged, not plug in.  However, I don't solo and my tandem partner is my wife, so if sh$t should ever hit the fan she'll be the first to know (she always is!)
That being said, I do have a 91 year old mother-in-law and my wife just didn't feel comfortable going off without having any way of knowing if something should happen to her.  What we did last summer was take a SAT phone with voice message capability.  No one was to call us unless it was an emergency and we'd check calls every evening.  Thankfully there never was a call and we found the whole process very unobtrusive.  Under those circumstances I was very happy that we had access the satellite techology, it allowed my wife to rest easy and when my wife rests easy, I rest easy - trust me.