Hello, Greg!
Last year I walked from SJPP to Santiago in September-October. I kept in touch with friends and family via e-mail and Facebook (mostly Facebook because in next to no time I could post a status update to the effect of, for example, "Hello everyone! 25km walked today, am here in lovely ________, had a beautiful day of walking on the trail... so many butterflies!"), and it worked well.
However, not every place I stayed had internet service/computers and because of that, it was two days before my mother could reach me to let me know that my father had died unexpectedly at home in Canada, of a heart attack. He died the night I was in Astorga, after I'd already checked in by computer for the day. The next night I stayed in Rabanal, no computer at the albergue, so she didn't know where I was or how to find me. The night after that, when I got to Molinaseca, there was a message from my mother on Facebook asking me to call home to Canada immediately. That's when I got the news.
My mother was almost to the point of contacting the police here in Canada to get in touch with the police in Spain, to see if they could find me, but I don't know how well that would have worked out. Next time I walk the Camino I'll keep in touch much the same way, e-mail and Facebook, and now my family and I have a better idea of how it is to stay in contact along the way.
(I'd bought a Spanish cell phone in Pamplona, by the way, but I didn't keep it turned on all the time I was walking, and in fact only used it about every 10 days or so; it was only after my dad died that I used the phone more often, to keep in touch with my mother in a more personal way than by computer.)
Enjoy your León-Santiago Camino! Last year I met a couple of lads from Germany who walked the same stretch (during their two-week school vacation!) and they loved it. Some of my happiest, most favourite days were the ones I walked with them. You'll meet great friends yourself, I'm sure. For me it was a lovely example of how it doesn't matter how long you walk with someone, great friendships can spark at any point along the Camino!
Buen Camino!
Rachel