1 cup ReadyBrek (http://www.google.com/search?q=ready+brek)
1/2 tsp sugar
1/2 tsp dried yeast
Enough orange juice to make the medium evenly moist but not sopping.
Incubate 8-24 hours then add AT LEAST 50-100 flies in order to keep the medium churned and prevent excessive bacterial colonization.
The least smelly medium I have found (but it still smells).