Thanks all for looking and taking the time to reply!
In our small Karoo towns the people are incredibly friendly, but also very inquisitive which makes it a lot easier! Sometimes people just see me with a camera and then invite me to come and take their photographs. Sometimes I 'bribe' them with a packet of chips or a lolly pop. Otherwise I just pluck up my courage and ask, more often than not I get a positive response. Just showing them pics on the lcd also works well. My plan is to get one of those small Canon portable printers to give them pics on the spot which should make things even easier!