The scene where Steve is being cornered by Stan, and ultimately saved by Francine is almost identical to the rescue scene in Terminator II: Judgment Day.
Roger and Francine's role-playing as a married couple is essentially taken from the Edward Albee play Who's Afraid of Virginia Woolf?
When Steve gets the snake's fang necklace from Makeva he is told "With this you will always have the heart of Africa." A reference from The Ghost and the Darkness in which Col. Patterson is given a necklace by Samuel, made with the claws from the lion he has killed and is told the same thing.
When the last race starts, the crowd shouts "Stevey bomaye". This is a reference to the Muhammad Ali vs. George Foreman 1974 boxing match, where Ali's Congolese fans chanted "Ali bomaye" ("Ali kill him") prior to and during the match.
When Hayley says she wants to hold a refugee's hand to show that someone cares, Stan laughingly said " OK, Bono, settle down," in reference to the U2 frontman's charity works in Africa.
The girl Steve meets and falls for is named Makeva. This is a reference to a character that Thandie Newton, who voiced Makeva, voiced earlier on the show ER, named Makemba Likasu, the love interest and later wife of Dr. John Carter, whom he met while in Africa.
When Stan sits in front of Steve when the camp has been raided, and says "I don't know what to do". Steve now slaps him in the face, imitates Stan, and tells him "You can act like a man!". This is a reference to The Godfather where Johnny Fontaine comes to his godfather, Vito Corleone, to ask for advice.