Was reading an excellent article on Open Gardens about Mobile Penpals by Stanford's RDVP program and frankly, this is a relatively simple concept to implement in any Emerging Market. Not only are phone pervasive they're also very personal, linking an individual with the "network" in ways that a computer might never be able to. You'll readily allow someone to use your computer to surf, check emails etc, but will almost never allow someone to use your phone beyond making a call or looking up a contact.
Having such a personal device, means that a user will most likely spend a lot more time on their device either communicating with someone via text message or building diaries or blogs about themselves and their families. Which in turn leads to more traffic for the operators and more "views" for the service provider (be it search engines or the social network facilitator).
Apart from the obvious financial benefits is the idea of bringing back the concept of Penpals which have been lost since the advent of email, just as the drop in snail-mail use worldwide occured when everybody caught on to the idea of being able to send "mail" to another person anywhere in the world, almost instantaneously. I know, some of you might say that we've moved on to the Internet or Web 2.0 culture. Penpals have evolved to become Social Networks, but there's something romantic about having Penpals and waiting a month to hear from them. Maybe because I grew up in that generation or maybe it's because I never had any when I was young.
There are many penpal networks on the web today (eg. www.interpals.net, www.epals.com, www.penpal.net) but none I know have brings "pals" together via mobile devices.
Someone should convince MySpace or Friendster to do something about it and quickly build mobile versions of their social network and ensure that anyone in the world can access it inexpensively. And call it Penpals for my sake :)
John Kuner's vision transcends just messaging but also allow users to make and share video diaries of their lives with their penpals half way across the world. Checkout his project's blog at Project VIEW .