hey, not sure about joburg, haven't been there... though sometime ago been to Cape Town on my own, i must say spent perfect time there. Haven't seen anything horrible and awful there, on the contarary, nice, friendly people. Of course I suppose everything depends on where exactly you are going to stay, if you have a hotel booking (!GOOD HOTEL!), planning to rent a car etc, if you have any friends or just people you know... in that case i guess not a big deal to travel alone... but me personaly wouldn't travel to Joburg, that's kind of a completely different story. btw, are you staying long there, i was thinking of taking a tour to SA again in the near future, end of may - june this year