What airlines regularly fly DC-3s (not charter or cargo airlines)? Any company in South or Central America?

"Aeroejecutivos" of Venezuela offer scheduled DC-3 flights. Check their website for further information...

http://www.aeroejecutivos.com.ve/ingles/home.htm

And check this website for even more information on the DC-3 (This aircraft is regarded by many as the most successful aircraft ever built)

http://www.douglasdc3.com/index.html