I'm going to say that of my "cohort" in college, email+facebook events were by far the most effective ways to get people to go to a place at a given time. Furt

I'm going to say that of my "cohort" in college, email+facebook events were by far the most effective ways to get people to go to a place at a given time. Further, I would wager my parents' generation do much of this planning via word of mouth at church. This is highly anecdotal though. (In any case, I think you overstate the set of people without computers but with cell phones from which reasonable social graphs can be generated. Some places cells are rare enough they are shared by a group of people...)