When I worked at a restaurant 90% of the time we never got tips on take out orders.
People would come in, get their to-go orders and leave. The other ten percent of the time, people would ask for the name of the person taking their call, and then tip, in cash, that person, but these people were few and far between.
I don't think I've ever tipped when getting take out. Then again, most of the times I get take out it's usually from a fast food place. Although I will drop at least a buck into the tip jar at the pizza place.
--Son Of Thrognar