Great comments and advice - thanks!!! I spoke briefly with my guide last night
(he was on his way out hunting with a client). I didn't get an opportunity to ask him about tipping, but we are scheduled to talk this weekend to make sure I have everything ready and I think that the tipping will come up in the course of our conversation. After reading the various comments, here's what I can tell you - my guide is also the owner of the concession (he's partners with his father-in-law). He seems to have several American clients, so it will be my assumption that he will likely be used to that kind of tipping. All of your comments are appreciated, particularly the article that Ripp posted and Steve Robinson's comments (since he's in SA, and that's were I'll be hunting).