Bitcoin seems like the perfect currency for developing countries, the only potential downsides are it's vulnerability to hacking and it's irreversible nature (which can also be a positive). It strips out many fees associated with banks or payment transfer systems like Western Union. It could potentially be stopped by governments if they make it hard to exchange into a local currency but people can be surprisingly creative when it comes to obstacles like that. I fear however that low tech governments would want to block it when they are scared off it by established payment processors who want to prevent competition.