Having spent enough time in various backwaters over the globe my experience tells me this usage scenario doesn't really work. If you're in an African village (and you're lucky to have cell coverage at all), your friends won't have fancy MMS capable camera-enabled phones (take a look at 1xxx and 2xxx Nokias, that's the kind of phones we're talking about). Furthermore, MMS (and internet) is considered a premium in those places and often costs more (even in absolute value) than it does in Western countries, so again, not exactly popular even if you have the hardware for it.