hi! have you already been to SA, or still going? its a beautifull country, with a certain wildness that steals your heart. i see you ere going to johannesburg, why? the western cape is definately the best part, but wildlife up north is also impressive!!
please be carefull, keep an eye on your stuff, try not walk around at night, lock your doors, etc etc. its really important!!
have fun!!
ps: see you're going to sydney too... i've been there too, enjoy!!