I was just wondering whether any airlines (or tour operators/air plane museums) operate flights with DC3s (or any of the DC4-DC7 models) on a regular basis?
(According to wikipedia there are still hundreds of DC3s around, but I assume most of them can be found somewhere in the developing world)

AFAIK the only model used on a large scale by major airlines is the DC9, most DC10s were retired over the last couple of years.