For basic use, wifi is widespread enough, especially at gringo hostels. Not sure about working, but I was contemplating bringing my laptop on my next SA trip and getting work done. What I worry about is how much of an obviously wealthy person I would appear as(relative to locals)if I set up my laptop anywhere away from the hostel. I dont like overt displays of wealth because it makes me feel icky, but it would also make me a prime target to rob. Im curious what other people have to say though...