Something is still missing in the world of mobiles and social networks.
I strongly believe in the power of social networks in development, be they online or offline. They create communities of practice from the local to the global level, which promotes better understanding of what a best practice is versus what is just a good theory that doesn't reliably work. You also have amazing, unprecedented access through mobile phones and SMS.
But there's nothing solidly connecting the two (unless I'm missing something?)
Naturally, you have a wealth of primarily-online networks (Facebook, Orkut, MySpace) which all have a mobile app or light version for smartphones. You also have MxIT, which is almost purely mobile social network/chat app, but still smartphone-only.
You also have twitter, which is a hybrid, but lacks an integrated system for creating communities (sure, you have hastags, twibes.com, and other third-party twitter grouping tools, but they all seem bolted on still).
And today, Microsoft launched their own, called OneApp, designed for Windows Mobile and java smartphones:
Microsoft is launching OneApp, an app for people running Windows Mobile phones with slow processors and not a lot of memory. Basically, it’s a lightweight app that lets you run more intensive apps by grabbing just the basics of that app that you need.
OneApp is an interesting tool that lowers the bar for smart-ish phones accessing the richer content of social media sites like Facebook, so it's a step in the right direction (and buzzword-compliant with talk of using the cloud).
You still need a decently fancy phone to take advantage of it, though.
I remain convinced that a pure-SMS or true Twitter-like hybrid social networking tool (fully functional for both web and SMS users) is a gap still needing to be filled. If it can't be navigated purely and cost-effectively for the users by SMS, it is missing a huge segment of the mobile population. It would have to remain pretty simple (a la Twitter), but combine more complex interactions (organic creation of groups of users around common interests) with increasingly intelligent and learning server-side tools to learn how much each user wants to interact. I feel that the UI would be the most painful part, as the user would almost certainly have to memorize the various commands (and issue them all via SMS). The usual malcontent spammers and such would naturally also be a hassle with the per-message cost structures of SMS.
Challenges aside, a SMS social networking tool could provide both the normal waste of time network with people sharing quotidian news, gossip and bad jokes, but also it could play a key role in engaging a new level of people around the world in discussions and information sharing.